Good crossover sports for practicing, wake boarding , snow boarding, land boarding. Cable parks are great if you have access to one.
+ 1 on the crossovers, my first board was a cheapo double tail plastic skateboard, i was probably 5. But still, at 48, I'll grab my skateboard and work on ollie's, reg & switch in the driveway. also work on switching my feet on the board to simulate tacks n jibes on a surfboard.
snowboarding is great for working your switch stance, can do jumps and ollies all day long.