i've made some flannel diapers when i was first learning. they came out really trim, but you need a LOT of layers, especially with a heavy wetter. i thought it was a great fabric to learn on and then you can venture out into hemp, velour, organics, etc. good luck!!
Mama to three sweet girls (a dramatic, chatty 10yo, a bouncy, dynamo of a 7yo, and a delightful, whimsical 3.5yo)