Difficulty level: moron
This was extremely easy to make, I just thought I would add it here as a simple, quick idea. I like it too because you can "undo" the bracelet if you don't like your creation after a while or want to change it up.
about 3 or more feet of a colorful 1'' thick ribbon
1. glue one end of the ribbon flat to the inside of the bangle
2. wrap the ribbon around the bangle (evenly, slanted a bit) until you reach your starting point
3. to cover the meeting point, wrap the ribbon one or two times around the beginning and end meeting point (not slanted)
4. make sure it's pulled tight and place the end of the ribbon on the inside of the bangle and glue in place. (if you have extra, just cut it off so the end and glue is on the inside)
5. let dry and wear!