The Doll Skirt Upcycle is a free pattern teaching you how to take a leg from a child sized pair of jeans or khakis and make a cute skirt for your American Girl doll. You can find the pattern here.
You can find a tutorial for making the ruffle here.
All you need is a leg from a pair of pants, some fabric scraps for the ruffle & a 9″ long piece of 1/4″ wide elastic.
I’d love to see what you make. You can post pictures on the Schoolhouse Patterns Facebook page.