However i will answer your question anyways because I do snowboard a little and can do 3's/claim
The most important thing for a BS 3 is to carve in to it hard and really pop off your toes. After that its the same as skiing, keep rotating your head and shoulders.SPOT.STOMP.BANG
For a FS 3 also carve in to hard but pop off your heels instead.
if he carves hard hes going to go cork, or at least thats what happens to me, maybe carve a little on your heels/toes, but not too hard or youll end up going corked, and thats a little trickier to land.
french fried when he should have pizza'd. rookie mistake.