Here is the t-shirt in question, which I believe dates back to the early 90's.

Simply cut straight across:
Then I just folded the top raw edge over and sewed it down to make a casing and inserted some 1/4-inch elastic. Easy!
Simply cut straight across:
A skirt that cost very little, that is comfortable (the most important factor to Millie), and perfect for play.
And she's off!
She did lots of climbing, running, and jumping in this skirt, and I was incredibly pleased with the fact that she had full range of motion, and also plenty of coverage.

Looks like I need to go find some more t-shirts to cut up.