I recently just found one and it was just falling apart. So, decided to do something with it and share it with you guys :D
nail polish remover (optional) and tape.
1. Clean your headband, also remove glue or anything that was left over. To clean it, I used nail polish remover.
2. Mark the design you would like to make on the headband. I used tape to expose some areas where I wanted to apply nail polish.
3. Use various colors to design your headband. Also, do not forget to put a clear coat, it gives a nice shine.
4. Let it dry completely. Finally take off the tape and show off your new headband.