I always like jeans & plaid flannel together. Probably not as long-lasting, but super warm & fun to have the different textures. Could be fun to do a houndstooth design with the jeans as the background & flannel/cotton as the "tooth" design -- or vice versa. I also saw once a Dresden plate done in overdyed denim. It was done as one of those ottoman-style pillow pouf thingies (sorry, not sure what they're actually called -- you can stuff them with shredded batting or foam or anything that's a little bit stiffer than regular fiber fill), but I don't see why you couldn't just make it smaller & use it as blocks in a quilt -- or just do one as a large applique.
Congrats on the weight loss! That's amazing. I'm trying to lose weight, too & hope to draw some inspiration from you to start making some progress. Good luck on the quilt. Should seem easy compared to losing all that weight!