What would be a good doll to make clothes for?

I like sewing and making clothes. However, I'd like to play around with clothing designs without having to worry about it fitting or looking good on me. I want to find a doll I can make clothes for, but I'm not sure what a good choice would be. I want something larger than a Barbie doll, and I thought about the 18-inch dolls like the American Girls, but I'd really prefer a doll with less childlike proportions. Any suggestions would be appreciated!