Sew the 2 shorter ends together to form a tube.
Gather your fabric using a loose zig zag stitch or elastic.
I like elastic to create an even gather. Sew your skit onto the onesie just under the arms.
You can add a band and/or bow around the skirt to hide the gathering or leave as is.
Luna Merza
I was thinking of making something like this too since cotton is not stretchable for the arm area to use during cold weather. Thanks for the sharing!
Roseann Nicolls
I’m wondering when you sew the skirt onto the onesie, do you have to use a stretch stitch so that the onesie will go over the baby’s head. Also if you pull on the onesie won’t it be stretched out and look wonky?