Here are my directions on how to make them:
You need:
1 piece of 25" x 4 " material
1 piece of thin elastic, 6" long
A sewing machine (or you can do it by hand if you have the patience)
a chop stick
tape
1. fold the material in half, long ways, right sides facing together and stitch
2. Turn the tube right side out
3. Tape on end of the elastic to the chop stick, run it through the material and scrunch as you go so you can reach both ends of the elastic
4. Stitch the ends of the elastic together
5. Fold over one end of the open end of the fabric to make a finished edge, slide the other end inside and stitch.