Worst thing you can do is put too much thought into it... just go for it. If you do them off diving boards then you know how its done, just pop and throw your upper body back (might help to swing the arms), tuck in your knees and pull your legs and skis up and around, and very important: look back with your head! If you commit with your head and keep looking back, your body will follow. And if the jump has a good lip and you come in with decent speed, don't worry about under-rotating it... you'll be scared so you'll over-rotate like a mother, which doesn't hurt too bad when you land on your back. Good luck my brother... and don't worry. Once you rotate it the first time, you'll realize how easy it is, and start hucking them like crazy everywhere.
--Disgruntled and Nostalgic Crazed Posting Bro!--