But since I didn't want to have to make a new apron every time her head grew, there was the problem of making it adjustable. I didn't have one of those buckles on hand, nor did I like the idea of tying ties at the waist and at the neck every time she wants to put on her apron.
Then I saw this apron (via this motherload list of apron tutorials), which is completely adjustable thanks to just one long tie. Genius!
Rough instructions should you want to make one:
Measure the kid and decide on your length and widths*, create a pattern piece out of paper and cut out one piece from cool fabric and one from muslin or bedsheet (or whatever you want as a backing). Sew right sides together, turn inside-out, topstitch, sew in casings along side edges, and finally thread through a tie (I use cotton twill tape).
*Final measurements for my two-year old's apron (add seam allowance if you want to make the same size):
8" from top to waist, another 7" to bottom, total of 15" long
6" wide at top, 12" wide at waist, 14" wide at bottom