Step 1 - Measure your child. First measure the length from her collar bone to her knee then add an inch or two for your hem. I only added one inch because I wanted to add trim at the bottom of both. Second, measure her width and double it.
Step 2 - Cut out your fabric. Ella happened to be 15" long and 9 1/2" wide. So I cut out 2 rectangles 16" X 19".
Step 3 - Right sides together, sew 1/4" seam down both sides of the fabric. Press seam open.
Step 4 - Sew your hem. If your adding trim, pin it to the right side of the fabric with the bottom of the trim pointing toward the collar. It may look like your sewing it on upside down, but once your done, fold the trim to the wrong side of the fabric and press. Starting at a side seam, topstitch all the way around the hem and your done with that part! I'm sure that was about as clear as mud. It's hard to describe some things without pictures.
Step 5 - Cut the arm holes. The next part you just have to be a little creative. I measured down each side 4 inches and over from the top 2 1/2 inches. Ella is wearing size 12 month and it worked great for her, you might have to make it a little smaller or larger for different ages. Then I just cut them out. You will be cutting through two layers of fabric so you better pin it so it doesn't slip. Be sure to curve the cut where the two measurements will meet (It will look like your cutting out a J shape). Turn the fabric under 1/4" under the arms, press, then sew in place.
Step 6 - Fold the Collars down according to what size elastic you have laying around. I had 5/8 so I turned the collars down 1". If you had 1", you would turn it down 1 1/4". Stitch around the bottom. Leaving enough space to slide your elastic through.
Step 7 - Take a safety pin and pin one end of the elastic to help you pull it through. After you pull it through one side, slide your fabric down the elastic until its bunched to a width you like. Cut your elastic and pull it out of the fabric. Cut a second strip of elastic the same length. Pull the elastic back through your fabric.
Step 8 - Attach your ribbon. After you pull you elastic through, cut 4 lengths of ribbon. You may want to practice trying a bow to see how much ribbon you need. I have no recommendation on ribbon width. I used 1" but I thought it was too wide, but others have commented that they liked it. Sew 1 of your ribbons to 1 end of the elastic. Slide the ribbon and elastic into the fabric so that the ends are hidden. Then topstitch the ribbon and elastic so that it won't slide anymore. I sewed over the existing 1/4 seam. Repeat three more times.