Get a few tough pallets, about 10, and create a simple obstacle and few platforms to develop your creativity. If I had a stack of 5 pallets, I go through my repertoire of going up it very quickly, so then I go on to doing it at different angles and trying from further away, in the case of sidehops and things like that. It kind of trains you to think about a simple slab in loads of different ways. I'm so used to riding in my garden that when I go to the local uni to ride, I can see fifteen lines in one spot. It's also good for fitness, because if you peel it back to basics, you can't cheat when doing stuff on square obstacles, so you start to get better quicker. This is just in my experience though, so try whatever you feel helps you progress and enjoy your riding