I like your ideas so far
For the 'pants' part I was thinking you could make a wrap around skirt from scraps of leather, trying to use the raw edges as much as possible...that is, if you're OK with wearing a skirt. I've made a few of them and if you hand stitch it and add things like wood/bone/stone beads, animal claws, leather strings and the like, you'll get a really cool look going.
Hope this helps! ^^