i use almost anything recyclable... Old jeans, old bath towels, old ratty dish towels, leftover batting from other quilts, old potholders that need recovering.....
I layer:
denim, batting, fabric...
denim, denim denim....
fabric, batting, insulbright, batting, fabric..
fabric, towel, insulbright, fabric...
fabric, towel, towel, fabric..
fabric, old pot holder minus binding, fabric...
it just depends on what I have on hand..