I started tramp lessons last fall, and I'll be starting up again this spring. I've been just doing exercises straight up and down, i.e. no sideways motion. Couple of things it's been good for -- first, I had a tendency to drop my shoulder and end up with a corked spin. Second, I would "unwind" too early and not be able to complete spins. I'm now able to keep looking over my leading shoulder until the right point.
Basically, it helps you to work on the basics. Also with the foam pit you can get used to inverts. ('m just starting on those).
I'm thinking of buying a backyard trampoline for this. I live so far from places that have them it would pay for itself in a few lessons I think. I was looking at maybe an 8' X 14' rectangle one.
For some reason I really want to learn a backflip. Not real sure why a 39 year old needs to learn that, but I'm determined to learn one. Mainly want to be able to do one on the ground, but if I could translate this to snowboarding it would kick ass.
If I got one, I would for sure use my skateboard deck with foam around the edges or buy one of the boards designed for tramps. Seems like a fun form of exercise anyway.