Hit the tramps and work on balancing your spins when spinning both ways. With balanced spins comes more confident spins and faster spins. Core and leg muscles power the spin, so train those. Also if you set your spin with a wider base and then bring your body tighter, the tighter your body is (the closer you are to the axis of rotation) the faster you spin. Theres some proper term for that physics stuff but I forget it. If you want an example of what I mean look at how trampolinists spin.... as penciled as can be. Obviously then you have no style but if you need to huck thats how its done.