How do you 360 on a mountainboard/snowboard?

It would be very different to do a 360 on a mountain board than on a snowboard. You have to come into the jump with some speed. On the take off transfer your weight to your heels or toes depending on which way you want to spin. Once you get to the lip pop off, spin your arms, and look over your shoulder. Then, looks down at your board, bring it up and grab it. at about 270 you should let go of the board, stretch out your legs, and spot the landing. Once you are about to land, absorb the impact with your knees. Ride away.