To make a denim purse from a pair of jeans, cut the legs off the jeans and cut along the back of the crotch seam. Pin the front crotch seam to one side, and sew along the seam to secure the flap on one side. Turn the jeans inside out, pin the jeans together at the bottom, and sew a seam along the bottom edge. Create straps from the leg material, and sew them to the waistband of the jeans.
Pin the crotch seam so that it lies flat, and sew through the original seam to secure the piece on one side. When pinning the jeans together, start at the center, and place the last pin 1 inch from the outside edge. Pull the extra material from the back of the jeans inward to create a fold, and pin the material in place.
Sew a 1/2-inch seam along the bottom edge of the jeans. To make the straps, cut two pieces of fabric that are 3 inches wide and 24 inches long. Hem the short ends of the material to cover the raw edges. With the material inside-out, sew a seam along the 24-inch edge of the material.
Turn the straps right-side out, and sew the straps onto the bag at the original waistband seam. If desired, add lace or appliqués to the outside of the purse.