there's really no way to just say how to cork because it all depends on the shape of the jump
for jumps with a lot of pop to them - DONT try and set the cork too early, start the spin off (i'd recommend going for a 7) then when your in the air drop back your left shoulder (if your spinning right) and bring your legs up to your chest, this will allow you to get off axis, when you want to go back to the right axis go open up your body and stick it
for jumps that send you longer (less lippy) - try and set the cork at the top of the jump, an easy way to do this is by carving off of the jump. As you get to the top of the jump try to be leaning with the jump. NEVER LEAN FORWARD! If you spin left, drop your left shoulder and reach for your right knee behind your back. This will allow you to get off axis. The further and further you want to go off axis the lower you reach on your right leg.
This might help you and might not it is just what i think of when i throw my corks.