The free dress pattern works for children up to size 18 months, and Tiffany shows how you can trace a current dress in order to get the right fit for the new pillowcase dress. If you don't have a spare pillowcase, look through the racks of your local thrift shop for a pillowcase that measures 40" x 20". No pillowcase? Simply substitute a piece of fabric that measures 40" x 40."
Get the Retro Ruffle Pillowcase Dress how-to from Simply Modern Mom.
Here's another ruffled pillowcase project based on an epattern from The Crafty Gemini.