I call this a 720 corkscrew because it has two distinct off-axis spins. Depending on how hard you throw it, the trick will sometimes become completely inverted, but the invert will take place during one of the two rotations. You can also tuck it up more and give yourself two and a half or three rotations. [INTERACTIVE_SLIDESHOW]
Try it on the tramp, in your front yard, or on a diving board, and then take it to the slope.
Take off on your right (or left depending on which side you lead with) outside edge. Utilization of the edge is key to setting your spin. After you pop off your edge, reach forward with your right arm and drop your head looking toward your left hip.
The rest of trick is dependent on how tight you keep your body. Tuck up tight and you will spin faster, open up and you can stall it out.
Feel out your spin until you've gone 540, then your landing will show up. Focus on the landing and come out of your spin. Drop 'em down, reach for that landing, and stay over your boards. Westside!