DIY towel-wrap with great photos, and even a pdf file for simple printing. You need a single towel (or t-shirt for curly hair) and elastic, or an elastic hair tie. Easy, I should be able to pump 6 of these out in an afternoon!
DIY TEE SHIRT HEADBAND :: Super easy! Make 6 cords from a t-shirt that are 50 cm each (or 3 each of 2 different colors). Make the easy knot like shown and delicately pull to tighten the knot. Tie the ends and wrap with an additional strip of t-shirt that you can hot glue on. If it doesn't fit around your head, use a hair tie or elastic headband cut into two 3cm strips and tie the ends of the headband to those!