Depends on how heavy you want the skirt to be...corduroy or flannel works best for wintertime threads..cottons and lighter fabrics are better for warmer weather. But really, it is just up to you. there are no 'rules' as to what type works best because they all do. I often mix corduroy and cotton on my threads. I usually try more to match up colors and patterns than fabric types. have fun and be creative!
You can use anything from fleece to lace. Just depends on what ya want. Cottons, lace (with underlining), rayons are nice for summer. Corduroy, polar fleece, flannels are nice for winter. Hemps pretty cool too, just kinda hard to find in stores and comes in a variety of different weights.