Video yourself practicing with no skis but boots on. Try take off with both feet and get a strong upward pop before attempting rotation and looking over the shoulder. Look at whether or not you are leaving off both feet. Then build to with skis on to try a contact twist 270' or even a flat full 360.

look over you shoulder people never do and they end up going off axis

Try to stay balanced right off of the jump. If you grabs it might stabilize you.

Spin your head hard and open your legs when the rotation is complete