Cut a strip of fabric 3 in by 15 in
Fold the strip in half length wise and sew the ends right sides together so you have a nice circle
Fold the long edges of the fabric under to the wrong side about 1/4 in and fold the whole strip of fabric in half. Sew it together leaving about an inch unsewn so you can put in the elastic.
Now, take enough 1/4 in elastic to fit comfortably around your wrist (make sure it is a little bit snug though it can't be to loose) and with a safety pin guide the elastic through the hole and all the way around the scrunchy back through the hole again. Sew the elastic ends together and sew the hole you left for the elastic closed.
That's it! These things are awesome! I have made a ton so far since they only take a couple of minutes. Have fun with yours!