I've heard several different tips on how to do it but the one that I like is when you come into the jump, make sure you have your shins pressed against the tongues in your boots so you don't land backseat, and then when setting the rotation, be patient but throw a normal 720 and just line up your vision with the tips of the tails of your skis. Then once you're airborn grab somewhere under the boot but if the grab is gonna make your spin awkward then just clench your core and wait until it pulls itself around, and after 540 it should drop you right into cork 7. Hope this helps