I made my first denim quilt years ago with squares of denim from old jeans and skirts for the front and use flannel squares for the back, sewed together with rag edges. you put the two squares together, sew an X in the middle, or a heart or whatever turns your crank, sew together in rows with half " seam allowances. Sew rows together and when you have it big enough, start cutting those seam allowances for ragging. That is the hard part, but worth it. If you use old jeans, you can get many color variations and it makes for a very interesting quilt.