I'll try and explain the easiest way to learn these, but I'm not sure how well I'll be able to put it in written words .

1. Start out going downhill, and then make a turn until you're pointing hill and you stall, then come down switch and make a turn out of it. Basically -- make a sort of W shape.

2. Do the same thing again, but when you start to stall, pop up onto your tail (whichever end is uphill). The tail of the board should stay on the ground, but the nose should come up.

3. Keep doing #2, starting the "pop" earlier and earlier each time, until you're doing a full 180.

You'll probably find that this is easiest to do from switch to forward, frontside (starting out on your heel edge). Once you can do it across the hill, try it going downhill at a relatively slow speed on an easy run .

Hope I explained that coherently!