from my experience this is what i see.
get comfortable on some bigger jumps. (pop them and shifty and grabs and stuff without spinning)
then try a 3 on a tramp or something where you are in the air longer than if you just did it jumping up from the ground
then try a 180 on the jumps.
right before you do it on a jump visualize that when you are at the top of the lip you wont be vertical (you'll be a bit back) so you want to make yourself more vertical by popping like you do for straight airs, that should correct this way2backseat epiphenomena.
(also popping is when you sort of spring off of the jump putting more weight back to the back of the ski before the lip and sort of ollieing at the top)
first time will probably be pencil steeze, but as long as you just get comfortable with the idea of spinning your body around you can change your style and stuff as you do it more.
also if i am wrong someone tell me, im no pro so i may have messed up a bit in my explanation