First cut fabric and elastic of size Fabric piece 1:16 inches by 6 1/4 inches and Fabric piece 2:10 1/2 inches by 2 3/4 inches, Elastic: 6 inches. Now hem the edges of the long piece of fabric with a very narrow hem.
Fold the smaller piece of fabric in half, right sides together and sew along the edge using a scant 3/8 inch seam allowance. Flip the tube right side out.
Use a safety pin and thread the elastic through the fabric tube. Secure each end with a pin. Sew a quick basting stitch to hold the elastic in place.
Lay out the larger piece of fabric, right side up. Line up the raw edges of the elastic piece and larger piece as shown below. Fold the edge of the larger fabric piece over as shown below and pin in place. Pleat the extra fabric on the back side so you are left with just enough on the other end to meet the ends in the middle.
Wrap the other end of the fabric around the elastic piece and pin in place. Sew along the edge using a 3/8 inch seam allowance. Trim excess fabric.