This is actually a rediculously easy trick.
When doing this trick, I suggest choosing somthing that steps down instead of a table top or spine.
It is very similar to doing a cartwheel, so you may want to try those out first. (That isn't required though...)
Terms that you should understand:
Backseat -- means that if you ride regular, you are going to be leaning on your right leg bending it more than your left. Visa verse if you're goofy.
--Important things to keep in mind --
1- You are actually fighting AGAINST the jump when doing this trick. Backflips you are letting momentum mainly carry you. With frontflips though, you are doing all the work.
2- You are blind for the majority of the trick.
3) This will be very fast at first.
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1) Find a jump that you are comfortable that is a step down.
2) make sure that your are angled perfect straight at the jump before you enter the tranny.
3) When you start entering the tranny for the jump, as odd as this may sound, you are going to slightly shift into the back seat. (This is done for the same reason you prewind for spins... to give you added power.) Try not to apply pressure to and edge, since it makes it a little more difficult.
4) Before your nose leaves the lip of the jump, you want transition all your weight into the nose of your snowboard. I'll clarify that -- since you can't convert power easily when you're not on the ground, you want to make sure that as your nose reaches the lip of the jump you've already begun converting that stored power you have from shifting to the backseat so that the moment your nose is over the lip, you've begun spinning.
5) Make it your goal to go for a nosegrab (or at least I found that to be the easiest grab when learning.)
6)For a moment you won't see the ground... maybe its because you're looking at the sky... duh!
7)But once you can spot the ground again, let go of your grab and spot your landing. (By opening up, you're slowing yourself down.)
8) I haven't been able to try this on powder, so I can't explain that landing.
But for harder packed snow, i always land with me weight between my legs and than slightly roll forward onto my lead foot so as to stick the landing.
9) Throw your hands up you have completed your first frontflip.
Hopefully this was beneficial. You'll noticed i taught you how to do them fast so that you will be able to easily complete the rotation.Later on, you can find the balancing point of making the flip slower and stylish since that requires feel for the trick -- as with everything.
Peace!