First try crossing up your skis a little bit and grabbing under your boot. This sounds stupid but it helps- on the lift cross up you skis and grab near the tail (inside of ski or not), that will give you the feel of it. Then try it on a jump, one you are comfortable with but can get a good amount of air, you dont wanna do it too fast. All you do is cross your skis up a little behind you and feel for the tail, it takes a lot of practice.
'Computer games don't affect kids; I mean if Pac-Man affected us as kids, we'd all be running around in darkened rooms, munching magic pills and listening to repetitive electronic music.' -Kristian Wilson, Nintendo, Inc, 1989