When I made rag quilts, I cut the top and backing fabrics the same size squares. I did 7" squares for lap quilts and 4" for baby quilts. Then I cut the batting into squares that were 1" smaller, allowing for the 1/2" seam line all around. I sandwiched the layers, quilted inside (I sewed a star) and then sewed around the outside edge just inside the 1/2" seam line. Then I started sewing squares together into rows, then joined the rows. When I had all the squares joined, I sewed all the way around the outside edge, just inside the 1/2" line, and clipped until my hands nearly fell off. Had to wash them a couple of times to get the fray puffy. I never used denim, but seems pretty heavy for 3 layers. Good luck. They really do turn out pretty when they're finished. Someone on this board had bought scissors that are for clipping rag quilts. I think they are spring action. If I ever make another one, I'm getting some :)