I cut the legging portion of the tights off. Then I cut each of those two pieces in half - so you'll have four peices - enough for two headbands!
I then sew two of the pieces together - you will have two seams. Make sure the seams are facing the same way, so when you turn it inside out the edges are both facing inward. Then I take one of the seams, scrunch it up, and sew it in place.
Take a piece of ribbon (preferrably the same color as your leggins), wrap it around once and sew it in place. Then wrap it around again so you create a loop which you can attach bows to.
There you have it! You're own little make-shift headband.