Handstand push-ups and handstand shoulder taps will really help build up your arm and shoulder strength. Make sure to keep a really tight core and legs during so you can create muscle memory for good form! Hollow holds and candle stick jumps (or single leg candle stick jumps!) are also good conditioning drills.
During the jump focus on pushing through your toes to get maximum height while going back and it will help keep your legs straight and toes pointed. If you cut the jump short and throw your head back, your legs will bend and your arms will most likely bend as well.
Once you get a video up, I'm sure a bunch of us could give you some specific pointers and drills to work on :)