Easy and quick pattern. Cut fabric 20-22 inches long and 4 inches wide. Sew the fabric together, right sides together using 1/4-inch seam allowance, making a tube. Cut 8 inches of 1/4 inch elastic. Turn the tube right side out. Using a safety pin, secure the elastic to the tube as you insert it.
Knot the elastic ends together. (Knotting the ends is much faster then sewing them and is very effective) Afterwards, take one end of the tube and cuff it to the inside. Tuck the other end inside the tube, sew across.
You can use leftover or scrap material if it's long enough.
I made a similar scrunchie using leftover satin from the bridal and graduation dresses my mom would make. Mom would give me all the scrap pieces and I would make barbie gowns and scrunchies from them. My daughter had a drawer full but of course she had her favorite ones, blue with white stripes, peach and white.