An old pair of jeans can be turned into a backpack. The seat of the pants is the right shape for a backpack, and the opening at the waist serves as the opening of the backpack. Denim is a thick, sturdy fabric, so strong stitches can result in a durable backpack. Other needed items can be found in the sewing department of a crafts store.
Cut the belt loops where they connect below the waist of an old pair of jeans and cut all the way around the waist to remove it. Cut the legs off 1/4 inch below the seat. Keep one pants leg.
Turn the jeans inside out. Fold the opening at the top down about 1 inch all the way around and pin it down to create the tunnel for the drawstring. Do not pin the opening where the zipper is. Sew a straight stitch from one side of the zipper all the way around to secure the drawstring tunnel. Start and finish the line of stitches with seven back and forth stitches in one spot so that they don't come out.
Sew the openings of the pants legs together so that the seat and legs form a straight line. This will make the bottom of the backpack straight and even. Turn the backpack right-side-out again.
Tie two old shoelaces together at the ends to create a drawstring, making sure it is long enough. Feed the end through the drawstring tunnel and position the knot that holds the two shoelaces together in the middle of the tunnel so that it won't be visible. Make sure the opening of the backpack is all the way open and tie the loose ends of the shoelaces together to secure the drawstring.
Cut two 3-inch-wide, 2 1/2-foot-long strips from the reserved pants leg. Fold the sides of the strips in lengthwise so that they meet in the middle and pin them down. Iron the folded sides to give them a crisp crease and sew the edges down to create the straps for backpack.
Sew the ends of the straps to the top of the backpack, on the side opposite the back pockets and about 1 inch from the bottom on each side. Run the stitches back and forth 10 times to secure the ends of the straps to the backpack.
Denim shorts or a denim skirt can also be used.