When I was a kid I loved to climb on walls and jump back down, or, if the wall was not too high to jump directly over it. And particularly this last is a very good exercise for the bounce.
I stand laterally of a low wall alternative (actually I didn’t found a knee high wall today nearby) – everyone must decide alone about the high of the wall, because falling is not very pleasant – and start jumping back and forth. At the beginning you can also stop over on the it to make it easier. Without breaks between the jumps it’s also a good exercise to increase the endurance.