Absolutely amazing easy bouncy super ball! All you need to make it - Rainbow Loom rubber bands and patience. I use rubber bands that remain after making bracelets and charms. As more bands you will use - as bigger will be your bouncy power ball. Start with few bands at once - twist them, tie a node and continue braiding and criss-crossing bands over this node. After 30 bands you will have a small super jumping ball. But be patient and continue to make it bigger.
This DIY Rainbow Loom Bouncy Ball which I made in my video tutorial jumps 7 meters high. Actually, it can jump higher if I would be stronger. The point is that bouncy balls rebound proportionally to the amount of force used when thrown at a hard surface.
So, have fun! Good luck!