Aren't they gorgeous?! The post was so popular that we've had multiple requests since then for a tutorial. Mary has been kind enough to let me go for it and share with you! I got to make my first set today and I have to say, that not only did it turn out super cute but it was also really fun to make!
This tutorial will work for any size of onesie. Whatever size you choose is what the finished dress size will be. (That may seem obvious, but some upcycles end up shrinking sizes. This one stays true to size.) I used a size 3-6m onesie for my tutorial steps.
For supplies you will need a onesie, some fabric, and 1/4" wide elastic. If you're using knit fabric, that's all you need. If you're using woven fabric for the skirt, you will also need 1/4" clear elastic to use on the skirt seam.