450 On.

1. Approach the rail at a 30-45 degree angle, riding straight in at a steady, controllable speed.

   A 450 is one and a quarter rotations: you end up in the same diagonal landing position as a 270-on (board crossing the rail at about 45 degrees), but you spin one full turn more before settling onto it.

2. Just before the rail, bend your front knee deep, close to 90 degrees, and crouch.

   Pre-wind your upper body (shoulders and head) slightly toward the way you want to spin, chest opening for a frontside rotation. Send your eyes to the spot on the rail where you want to land.

3. Pop off the tail with an ollie to get height, and at the same instant unwind your loaded shoulders to start the spin.

   All of your spin momentum is set right here at takeoff; you cannot add to it in the air. Because it is one turn more than a 270, commit to real height to buy yourself airtime.

4. Once airborne, pull both arms and both knees in toward your center and make yourself as small as possible.

   With the same momentum, a smaller body spins faster, and that is what carries you through the full turn plus the extra quarter.

5. As you finish the first full turn with a quarter left, look back over your shoulder to find the rail, aiming so the line from nose to tail will cross the rail at about 45 degrees.

   Open your tucked arms slightly to brake the spin.

6. Set both feet onto the rail at the same time, weighting the balls of your feet and your heels evenly, and drop your hips (center of mass) directly over the rail.

   The moment you land, tighten your abs and lower back to stop the rotation cold and hold a boardslide.

7. At the end of the rail, turn your chest to face downhill, slide the board off straight, and bend both knees to absorb the landing.

You can pin your own clip to the tricks you've landed (My Video).