Skateboard more. It is a very explosive move that requires (IMHO) a lot of explosive power in your legs. Getting solid with a skate ollie helps a lot.
Something my buddies and I do when the lake is chopped up is ride about 25 ft out around 20ish mph and play around on the wake like a spine ramp, ollie re-entrys, stuff like that. Simply build those muscles and really focus on the movement being a powerful ollie.