denim quilts are not difficult- and they make wonderful raggy quilts! people love them because they are heavy-warm- and there is just a timeless-ness about recycled denim.
my mom (who lived in a lighthouse for a number of years) used to make 15-20 denim patchwork quilts every winter- then sell them in the lighthouse gift shop in the summer -tourist season-
people would snatch them up quick!
she used cotton batting in them (liked them --meaty) with squares- of denim top and bottom- 1//2"seams- double stitched. she made mostly twins- use a good new sharp (or denim) needle- and good strong thread- they are no more difficult than any other cotton fabric.