Best thing I learned was to learn how to really follow through when you're jacked up like that.
Now I feel pretty confident with most jump shots, even when playing with my full playing cue. I guess I'm stuck in the past, in that I agree with the likes of Earl that jump cues shouldn't be allowed. So I don't jump with a jump cue, but rather choose to jump with my playing cue. Just hit the contact point where you want, and pay extra super attention to following through with a strong stroke. It takes getting used to with the jacked-up position, but I've taught people in only a few minutes... you just have to get used to it and not be afraid to really hit the ball.
Ooh, also: a lot of people hit the cueball too high (along the vertical axis). Play around with it, and don't feel like every jump shot has to be a full-ball jump at only 6 inches away. You'll learn a lot about the shot and the mechanics behind it when you progres your way up.