Showing posts with label Tailor. Show all posts
Showing posts with label Tailor. Show all posts

Wednesday, September 6, 2023

How to make dress mannequins for 18" dolls...

Finished dress mannequins.

       The sample dress mannequins shown here are for an 18" American girl doll and an 18" BFC club doll. 
       Dress forms or dress mannequins are used when sewing for people or dolls. It is much easier to size, drape and remove fashions from these forms than it is to do so directly onto a doll or person. Plus the pins won't stick, ouch!

 Supply List:

  • scrap sheets of quilter's batting
  • wide masking tape
  • cotton batting filler (stuffing)
  • the doll that the dress form is made to fit
  • a wide dowel rod
  • a wooden candle stick
  • acrylic paint for the candle stick
  • old, tissue sewing patterns recycled
  • Mod Podge
  • aluminum foil
  • wood glue or hot glue with gun

Step-by-Step Instructions:

       To make an accurate, life-size dress form you will be shaping the mannequin directly on top of a doll to begin with. Lay the quilter's batting flat on the floor and roll the doll on top of it to form a tube beneath her arms. Using masking tape close the tube, making sure that the tube is snug about the doll's figure. This tube should be cut short just above the doll's knees.
       Now wrap the quilter's batting about the doll's shoulders and neck. Cover all of this shoulder wrap with masking tape to and overlap some of the tape down onto the torso. (see pictures below)

Left, you can see the quilter's batting sheet is wrapped snugly around our doll's nude torso.
Center, above the batting sheet is also wrapped about the doll's shoulder and includes her
collar bone as well. Right, the entire wrapping of the doll is done with two layers of
masking tape.
 
       Next you will need to remove this form carefully with a pair of scissors. Slip the scissors up the front side of the doll, between the masked cotton and the torso of the doll. Do this slowly and carefully without cutting any of the original body or hair belonging to the doll.
       Gently stuff the shape of the dress form with cotton batting around a wooden dowel rod that should be suspended in the middle of the dress form. This rod should be as long as the torso and stick out at it's bottom at least an inch.
       As needed, pack the neck and arm openings with cotton and then neatly tape across the holes closing these permanently with the tape.

Left, cup all the way up the front of the dress form between the doll's body and the inside
of the wrapped quilter's sheeting. Right, tape together the dress form at the seam where
 you have cut it away from the body of the doll.
 
             The photo above on the right shows that I have suspended the dowel rod through the center of the dress form with tape on it's end. Pack the cotton fluff around this dowel, keeping it suspended in the middle during this process.
 
Left, see how I taped the inside of the dress form shut. Right, the dress form next to the doll.

       Above you can see how I stopped stuffing the dress form approximately one inch from the end. This is because the bottom of the doll dress form was completely filled and packed with the stuffing and I wanted to hide the dowel from view inside of my wooden candlestick opening. You many need to line the inside of the candle stick with aluminum foil to make the opening narrow. 
       Mask on top of the foil and around the upper portion of the unseen candlestick. Fill the hole with wood glue or hot glue and firmly insert the end portion of the wooden dowel inside, attaching the dress form to the candlestick.
       Finally, after the glue has dried and the candle stick firmly attached, the dress mannequins are ready for decoupage. This end step will harden the exteriors of the dress forms further and give them slick finished surfaces that are easier to fit and drape over during sewing. I chose to recycle old sewing tissues for this final step. Layer these between Mod Podge applications and let the mannequins dry overnight. See pictures at the top of post for the finished result.
Left and Right, here you can see that I've wrapped the torso of a BFC doll using the same method.

       I also made a dress form for our Best Friends Club Dolls. It was much easier to cut the dress form away from the doll because her body is made from hard plastic instead of canvas. 

Left, the dress mannequin is wrapped and ready to decoupage. Center, one of our BFC dolls
stands next to her dress form. Both mannequins side by side to compare the doll body types.

Dress forms or mannequins decoupaged with old tissue sewing patterns. As seen
 left, back, center, details and right side back. The front views are at the top of this post.

Saturday, May 28, 2022

DIY AG doll robe from a pillowcase...

Left is the robe cropped and hemmed at the knee. However, you can make this robe as long
or short as you like. Right is a close-up of the silky sleeve finished in red.

       You can sew a lovely kimono style bathroom for an 18" doll from a silk pillowcase. Then trim it with lace or fur, whatever you prefer. Both examples shown here have silky ties made from the same matching fabrics and fuzzy house slippers too.

 Supply List:

  • one pillow case (Ours came from a dollar store.)
  • ribbon/lace for trim 
  • needle and thread to match
  • tape measure

Step-by-Step Instructions:

  1. Measure the length of your doll's arms and chest combined. This will determine how much of the robe must be cut lengthwise for the doll's sleeves. Ad an inch to this measurement so that the sleeves may be turned under by a little and finished neatly.
  2. Place your doll on top of the pillow case at it's opening in order to determine the length of your doll's robe. Making sure to leave the pillowcase hem intact at the bottom of the robe. You can decide to make a short summer robe or a longer winter robe.
  3. Now you will need to cut away the excess fabric from beneath the robes arms, leaving enough fabric for the doll's torso to fit inside the robe comfortably. (See photo below on the left.)
  4. Cut a "V" shaped opening at the neck. (See photo below on the right.
  5. Turn the front and back sides of the cut robe pieces right sides together and sew the arm and shoulder seam.
  6. Sew the seam under the arms and down the length of the robe's sides.
  7. Turn the robe inside out with the right sides apart and press the garment with an iron.
  8. Finish the remaining edges with a straight seam and ribbon.
  9. I also sewed a lace trim on the red and white version of this pillowcase robe.
  10. Sew a long sash or a ribbon to keep the robe closed on the doll while she is wearing it. (See photo below.)
  11. You may also wish to tack on a few ribbon loops to the side seams to hold the sash or ribbon in place neatly.

Left, this robe is made from an altered dollar store pillowcase.
Right, the 'V' neck cut at the collar of the robe.

Left, the pillowcase robe trimmed with lace and ribbon also has a silky tie for the waist.
Right, the finished robe tied at the front with a silky bow.

More Ways To Sew a Doll's Robe:

Left, this robe design can look very different if made with fur lined sleeves and lime green trim.
See the sleeve close-up with lime green trim. Right, the full-length of the black and white silk robe
for a "My Generation Doll." This robe will fit any 18" doll type, including American Girl Dolls too.


Monday, October 25, 2021

Winter Flannel Nightgown Pattern

       Above you can see the finished baby doll nightgown sewn from lavender, dotted flannel. This doll measures eleven inches long and the length of her arms across the chest, measures nine inches. 

Instructions for Sewing the Flannel Nightgown:

  1. Print and cut out the outer gown of the pattern first. 
  2. Lay this pattern out on top of a folded piece of flannel with right sides together. Pin it down.
  3. Cut out two pieces, front and back. 
  4. Sew the flannel nightgown together at the shoulders first using a straight seam.
  5. Then cut out the sleeve patterns from the print in the same way with right sides facing together, two pieces of flannel.
  6. Sew, gather and tuck if needed the sleeve into place on the garment at the shoulders first.
  7. Now sew a single, long stitch running along the length of the sleeve down the sides of the gown, right sides facing together. Repeat for the opposite side.
  8. Turn the nightgown inside out and sew a hem at the bottom opening. 
  9. Cut a three inch opening at the top collar in front for the doll to slip it's head through. 
  10. Line this opening with a ribbon to finish the edges.
  11. Clip a small tab and attach snaps to it and at the top of the opening. (see photo above)
  12. Attach the tab using a whip stitch so that the collar may be closed with snaps or Velcro or a button alternatively.
  13. Finish the sleeve openings with the same type of ribbon that was used to finish the collar with.

Click on the image to download the largest available size and print.

More Winter Pajamas for Baby Dolls:

Thursday, October 21, 2021

Sew Footed Baby Doll Pajamas

This tiny baby doll is filled with plastic pellets and he is the perfect size for an 18" American
Girl doll to carry about and play with as a younger sibling. He wears Summer sleeveless 
pajamas to feel cool but cozy while he sleeps!

        This doll is so small, 8 1/2", that you only need a few scraps of fabric to make a pair of pajamas for him. The seam for a tiny doll like this one is quite narrow, 1/8", so if you are worried about working with something so narrow and fraying it in the process, elect to use a fabric like felt or fleece so that you won't need to finish the edges. Felt or fleece does not need to be turned under, it may be finished with ribbon instead.

Sewing Instructions:

  1. Cut the pattern out below. 
  2. Clip apart the shoulder seams at the top of the pattern between the dotted lines very carefully.
  3. Trace around it with a soft pencil or piece of chalk. 
  4. Cut the one piece footed pajamas out.
  5. With the right sides faced together, fold the cut fabric under the arm holes, matching up the footed parts and pin into place.
  6. Sew one continuous straight stitch from underneath one arm hole all the way around to it's opposite arm hole. 
  7. then sew together the shoulder seams. 
  8. Turn the pajamas right sides out and turn under the sleeveless arm holes and collar to finish these.
  9. Now add some trims: a bow and tiny pointed collar if you like. I also cut felt pads for the footed parts and embroidered these on. Any trims are merely optional and decorative.
  10. Lastly, attach a snap up at the top of the back collar. If you prefer use Velcro instead.
The back side of our baby doll's footed pajamas is show above, including the placement
of a snap for closure.

Click directly on the image to download the largest size, this pattern will print to
exactly fit a 8 1/2" baby doll without altering it's size in a software program.

More Pajama Baby Doll Patterns for Your Dolls:

Sew Cute Reversible Doll Baby Bibs...

This doll bib has two nice sides, Left is a bumble bee print combined with an embroidery of the same
insect and Right, is the backside of that same bib that has a star print on it. The doll shown above is very
 small but the pattern page below has many sizes of bibs for you to choose from.

       Sewing  a baby bib for a favorite doll is an easy first lesson for a child. All you need for this DIY is a printable from below, scrap fabric, a needle and matching thread, ribbon and an embroidered decal is optional. 

  1. Print and cut out your bib options and hold these patterns up to your doll's chest to determine that size you will need to sew.
  2. Use a soft pencil or piece of chalk to outline the shape of the bib on top of the wrong side of your fabric scrap. 
  3. Cut out the bib leaving a 1/4" seam allowance.
  4. Lay this scrap out on top of the right side of a second choice of calico and cut out a second side the same as the first. 
  5. With right sides together, sew a straight seam around the two fabric pieces leaving an opening of approximately one inch. 
  6. Turn the bib inside out and whip stitch the opening closed. 
  7. Press with a hot iron.
  8. Cut out a ribbon to stitch on top of the neck of the bib. Give it enough length to tie an easy bow in the back of your doll's neck.
  9. If you have an iron on embroidery patch, now you may attach it to the side of your choice by heating up the iron and firmly pressing the embroidery in place. 

Swipe the my pattern onto your desktop and print it for this project.

More Baby Doll Bibs from The Web:

Wednesday, October 20, 2021

Snowflake Swaddle Pattern by kathy grimm

Both of these baby dolls, on the left is a Water Baby,  have arms that measure nine inches across,
 from finger-tip to finger-tip. However this pattern could be used for any 10" to 12" doll because
it has no sleeves.

       I made this snowflake swaddle bunting for our eleven inch baby dolls using a recycled sweat shirt made from white fleece. I also added two metal snaps just above the doll's shoulders to attach the swaddle sack to the doll. You could use buttons or Velcro instead if you prefer. This is a great little sewing project for beginning sewers and it's also a perfect gift to give during winter holidays!

Instructions for the Swaddle Bag or Bunting:

  1. Cut two swaddle sack sides, front and back. 
  2. Pin right sides together and sew a straight seam around the sack from under the arm holes. 
  3. Turn the sack right sides facing out. 
  4. Cut four shoulder tabs and repeat the same step, without sewing the ends together. 
  5. Then either sew a lining tape to finish the edges of the upper portions of the arm holes and collar or simple turn these under 1/4" and sew them down in order to prevent fraying. This step isn't necessary if you are using fleece but it makes the swaddle look professionally sewn.
  6. Attach the finished shoulder tabs with a whip stitch at the back of the swaddle onto the shoulder sections. (see photo below)
  7. Now attach snaps or buttons or Velcro, to the tabs on the inside at the back and also to the front of the swaddle just below the doll's shoulder.
  8. Use embroidery floss to hand stitch similar snowflakes if you like...

Here you can see that I used snaps to attach the bunting over the doll's shoulder.

More Bunting Patterns/Directions From The Web:

The swaddle sack, or bunting, has embroidered blue and grey snowflakes across the front.
These originated with the recycled sweatshirt.

       My free pattern below is designed to print out for ten to twelve inch baby dolls. If you are uncertain about the size printing properly, I have also included the arrows on the pattern to match up with a ruler inside of Word software. The bunting should measure 9" from the mid-point of the collar to the mid-point of the bottom of the sack.

Click on the pattern to download the largest size, this one will print for a 11" baby doll.

Sunday, August 1, 2021

How to make handker-shifts from 1966

        This retro, fashion doll article first appeared in The Australian Women's Weekly, 1966, by Jenny Irvine. It is archived online by the Bauer Media Group as historical content.

      "Well, here's a novel use for your surplus Christmas hankies this year. You can make a wardrobe of smart summer outfits for a teenage doll.
      It takes one handkerchief for each outfit and only a few hours to make them all.
      You can have marvelous fun designing "handker-shift dresses incorportating the floral boarder, lace edging, checkered pattern, etc...
      We made a two-piece beach outfit with a scarf, a smart town ensemble and a dreamily romantic evening gown -- All from hankies!
      They were all made from the average 11in. square handkerchief - the first two from cotton handkerchiefs and the evening gown from an Irish linen, lace bordered one.
      The town ensemble was dressed up with flower motifs cut from pink broderie anglaise and a pink mob cap to match centered with a circle of the same material as the outfit.
      The evening dress was more difficult to make than the other two outfits as we added sleeves, beaded the gown, and made a circlet of pearls to wear as an accessory on the doll's head." Jenny Irvine.
 
Teenage doll dressed for town in an ensemble with a mob cap
 to match. Graph, left, shows how to cut out the dress.
Each square represents one square inch.
 
The Town Ensemble: Instructions: "Hem both cut edges of skirt dress. Fold material so that the bordered edge of the handkerchief is on the right side, and hem. Pulled on to the doll, the skirt-dress hangs from above the bust and will be knee-length.
       To make the scarf, hem the cut edges, fold the square in half to make a triangle, and attach the points of the triangle with a lace motif or beading.
       Placed around the doll's shoulders with the triangle point at the back, the scarf forms a high collar. To keep in place, use a press-stud to hold the scarf to the skirt-dress.
       The hat was made from a strip (7" by 2") of broderie anglaise, Gather one side of the length with cotton. Join the material to form a circle.
       On top of the gathered ends, place and sew a small circle (one inch in diameter) of the same material as the outfit. Attach to doll's head with a pin."
 
This doll's evening gown could easily be used also as a wedding dress.
 
Evening Dress: Instructions: ''See graph above left. Hem the armholes to prevent fraying. Attach the sleeves, which are cut so that the lace hangs below the elbow. Fold cut edge inwards flollowing fold marks on pattern- the armholes should be the guide with the fold falling dead center from three markers.
       Sew the cut edge to the inner side of the lace border, then sew down the lace border on the material so that it falls in a panel, center of the gown. Sew only as much as 7 1/2inch., taking your measurement from the lace hemline. Fold the remaining lace on both sides back to form a collar. Bunch the lace and sew down to prevent it being too wide and cumbersome.
       To bead the gown, follow the lace edge hemming of the handkerchief and also bead the collar."

For a day at the beach, but not for swimming.
 
Beach Outfit and Scarf: Instructions: "See graph above left. Join side seams of jacket and right shoulder seams. Sew press-studs on left shoulder seam after hemming edges. Hem cut edge of skirt length. Sew pleat down and hook together wit press-studs down left-hand side.
      For the scarf hem, cut edge and tie around doll's head."
 
More Handkerchief Doll Fashions:

Sunday, July 25, 2021

Simple Summer Length Wrap Skirts for 18" Dolls

        You can sew a whole set of wrap skirts for your dolls either by hand or on a machine. Make them decorative on both sides and your dolls will have many more optional dress prints to wear!

Kit wears a tropical blue print and her friend wears a traditional Japanese print
in golds and yellows.

Doll wrap skirts, Left front, Center, back and Right from a distance.

On the far left and center are my doll's reversible wrap skirts in order,
front to back. Far Right, is a photo of a whip stitch.

       The supply list and directions for this doll sized, wrap skirt below is for a short version. You could lengthen the fabric measurements to make a longer version instead, if you prefer.

How to tie a wrap skirt.

Supply List for One Skirt:

  • needle and thread to match
  • two decorative fabric pieces measuring 5 1/2"x19"
  • a length of ribbon measuring 33" long 
  • sharp scissors

Step-by-Step Instructions:

  1. Cut two identical lengths of skirt fabric. I cut a gentle curve off of the two sides, but this is optional. (see photos right)
  2. Lay the two pieces on top of each other right faces together.
  3. Sew a straight stitch around the outer edges leaving 1/4" seam allowance.
  4. Leave a 1" opening at the top somewhere and turn the skirt inside out.
  5. Press the skirt with a warm iron so that the seams are neat. 
  6. Whip stitch the opening shut.
  7. Cut a length of ribbon measuring 33 inches.
  8. Center and sew the ribbon across the top of the skirt using any stitch you like.
  9. On the front or back side of the skirt, measure a length of approximately 5 1/2" and poke a small whole in the fabric with the sharp tip of your scissors. This will be the small button whole you will need to insert the ribbon tie through when wrapping the skirt on to your doll's waist. 
  10. I hand-stitched a button whole using a matching thread. Go here to see this done at YouTube. If your doll's fabric wrap skirt is made of felt, you will not need to do this step.

More Wrap Skirts for Your Dolls:

More Doll Skirts from Our Blog:

Thursday, August 13, 2020

11 Things to include inside a young student's first sewing kit

Sewing class from the early 1900's
  1. A needle threader – Small fingers and inexperienced eyes can not always keep a needle threaded properly so, keeping a needle threader on hand is a very good idea.
  2. A pincushion is sometimes included in a fancy little sewing basket. But, no matter what type of kit your student chooses, he or she should have a small pincushion included in it. Many teachers choose to assign a pincushion first before all other projects are considered. This is a traditional introductory lesson for any person learning to sew.
  3. I prefer tiny scissors to a seam riper for children. A seam riper in a beginning sewing class or workshop for young children, is an accident waiting to happen!
  4. A small variety of threads – Threads come in very small quantities at sewing shops. It is easy to find tiny spools of thread even in the grocery store. Black, white, navy, red, yellow, pink and pale blue cotton thread are all quite common in these small packs.
  5. Sampling of buttons – Students will use odd buttons for decorative purposes or for practice in a beginning sewing class.
  6. Her own needles – Students should never share their needles with each other under any conditions what-so-ever! Make this a class rule. The teacher may keep extra needles at her own desk for those students who forget their own. Students should not return the needle to the teacher after using it. In order to prevent the transfer of illness this rule must be reinforced in the classroom.
  7. A white piece of chalk is needed for marking fabric. There are also fancy marking pens that older students may wish to purchase.
  8. A small tape measure – This is a must even for little kids because it incorporates basic math skills into their sewing projects. Teachers may wish to print and cut these out to help save money on the kit supplies.
  9. Band-aids are a must for a kit.
  10. Antiseptic spray or an anti-biotic cream is also very important as well inside of any sewing kit. Those needle pricks will occur and they heal up fast with medicine on the spot.
  11. A thimble to protect tender finger tips!

What Should a Beginner's Sewing Kit Look Like?

sewing kit
       A student’s first sewing kit could be a simple basket, preferably with a lid or a small plastic container. Sometimes teachers prefer to purchase plastic containers all at once for a discount. This also guarantees that the kits will be of uniform size and appearance. Teachers may choose to stack kits neatly on a shelf during the school day. Some students are too forgetful to be trusted with bringing a sewing kit to class when it is needed. Boys can also be a bit self-conscious about packing a sewing kit into their backpacks as well. Personally, I prefer to give the task to the student of “scouting out” their own sewing kit. I believe that individuality and personal choice should be rewarded to a child’s artistic pursuits whenever possible. Encourage the girl who wishes to purchase a small attractive basket or an unusual box for her first sewing kit. Have examples of many small kits on hand to show your students the possibilities. Make sure that several of these samples are not too feminine in appearance or very expensive to collect.
      Here is a linking list to several versions of sewing kits that parents may acquire for their children to use. These kits make wonderful birthday gifts for a young girls. I’ve also included a few links to historical versions of sewing kits as well.
      If you are a parent homeschooling your children and wish to teach sewing skills, you may consider gifting a child with a kit designed for sewing fishing lures. A bait and tackle box is an excellent alternative for a child who prefers this form of entertainment. Sewing skills need not be about clothing. This would also be an excellent winterim course for middle school students after Christmas break in a private school. These brief courses are usually taught for fun and faculty members are always on the look out for new ideas. Girls frequently gravitate to small needlework or quilting classes. However, for those students less inclined to sewing garments or fancy work, bait and tackle boxes have fun possibilities. These make great gifts for a dad if sons or daughters don’t fish. If you intend to teach this type of course make sure that you acquire a good quantity of feathers and specialty products along with a basic manual before starting. There are actually films available that give instructions for crafting lures as well. Make sure that you have some “fish stories” and other fun activities to mix in with the threading or your student(s) may take a nap, well, it is fishing.

Friday, May 22, 2020

Sew Quick Summer Skirts!

Two of our dolls wearing cool summer skirts in the garden.
       These little summer skirts are very versatile for a variety of doll waist sizes if made with elastic waistbands. These fashions fit Our Generation Dolls, Journey Dolls, American Girl Dolls, Madam Alexander Dolls and Magic Attic Dolls from our collection.
       To make skirts like ours you will need to recycle a baby or toddler jumpsuit with elastic leg openings. From one jumpsuit, we made three items of clothing, two skirts and one dress. Here I will describe to you how I made the skirts. In a later post, I will explain how I made the dress.
       You will also need scrap fabric lengths measuring 19" x 7", a flexible fabric tape measure, lace, rick-rack trim, needle/thread and additional novelties for accents.
       I held a flexible fabric tape measure onto the outer edge of my recycled leg openings on the jumpsuit in order to measure just how much additional fabric I would need for the short summer skirts. I needed 19" lengths of fabric to pin and sew onto the recycled pieces with straight stitching. 
       My doll skirts measure seven inches from the waists to the top the knees on each doll photographed here; that includes the lace and the 1/2" seam allowance at the waist and 1/4" seam at the hem. However, the length of the skirts will depend on taste or fashion.
       I also added a bit more trim to the skirts, blue rick-rack and white lace for one and a white embroidered flower with lace for the other example. 

Left, is the aqua checkered print jumpsuit that was worn by baby. Center, you can see that I have cut away 
the elastic binding, snap and approximately 1 1/4" of the fabric beyond the leg opening. I will then attach
 fabric to each in order to make the quick summer skirts. Right, I chose playful green and blue prints
 for my skirts, plus white and blue trims.

Shown are dolls walking through our kitchen garden in the finished skirts.

Thursday, April 9, 2020

How To Alter Leggings for Your 18" Dolls

       Leggings are perhaps the most common fashions worn by young people. The fabric usually dictates whether or not the legging is suitable to wear in public. Although, I have frequently seen a college student roll out of bed and adorn pajama bottoms to class along with a matching sweat shirt!
       Generally speaking, if leggings are made from flannel they are considered sleep wear. If they are made from fleece fabric, they are considered athletic wear and finally, if the legging is made from a fun knit print, children will where them anywhere!

Left, all four sizes of legging that I show here are 3 months for babies. Center, I cut the sides
only of these small life size sweat pants so that the detailing of the front opening and the pockets
would remain a part of my doll's version. Right, five altered leggings from left to right, flamingos
 on a knit print, stripes with stitched details and navy cuffs, polka-dots on a brown fleece, a fancier
navy and white print and finally, a solid hot pink with pink stitching on the bottom.
        However, if the legging is for a doll the how and wear of it is always cute! It is also very simple to alter leggings from a real life infant size to a doll size!
       Pull the leggings onto your doll and use straight pins to mark how much material on both the right and left leg that you will need to remove from the outer sides. If you are altering a small infant size legging, you will only need to make the outside leg adjustments, leaving the inner leg stitching intact. Remove the pinned legging from the doll and carefully cut away the unwanted fabric, leaving enough behind to sew a 1/4 to 1/2 seam allowance down each outer side. I don't even bother to remove the old elastic at the waist, I just alter the waist along with the pant legs all at once.
       After sewing the new narrower pant legs using a straight stitch, I then run my doll leggings through the machine using a zig-zag stitch to keep the material from unraveling.

Left, you can see me cutting and measuring the baby leggings to fit my 18" doll.
Center the leggins are altered and on the doll.
Right, here is a comparison of doll leggings against an infant size in real life.
       If I am measuring and cutting to alter a larger child pair of leggings, I will cut off the waistband to fit the doll and leave enough excess fabric to make a new gathered waistband to fit my doll's waist. This usually requires 1 1/2" of fabric at the top of the waist band along with a 1/4 to 1/2 inch fabric down the left and right side of the altered sides to make an acceptable alteration. Sew up the side seams with wrong sides together first.
       Then fold back the 1 1/2" seam at the waist on the inside of the legging. Turn under a consistent narrow seam to create a long narrow pocket at the waist, leaving open 1/2 inch for the new elastic to be inserted. Clip a safety pin through your elastic and thread it through the pocket for the waistband. Pull both ends together through the opening and sew a very strong short seam across the two ends. Clip the excess elastic away and tuck the rest back in. Whip stitch the opening shut. 
       The amount of elastic you will need for your doll's waistband will depend on the type of doll you have. I do not use exact measurements when using this notion. I do something my grandmother once called "eyeballing it" which means to determine the proportions by guesswork. In other words, look to see what appears most pleasing in the gathering of the material as you sew with it. Some people like tight waistbands in their doll leggings, some folks don't.

Left, a doll size legging compared with a 3 month old size. Center, a legging sewn for a doll in red
 from scratch compared against an altered pair cut from a 12 month size. I will need to hem the
bottoms. Right, another stack of leggings for our 18" dolls. Most of them are floral prints but the
 one on top is a grey pair of doll sweat pants.