1. Often you need to stall a little bit at the top of the wave and wait for it to get steep. You should aim to put your board right beyond where the wave is curling--right where it's really steep.
2. From there, I try to do an over exaggerated snap. The turn needs to be done slightly higher on the wave face than a normal snap would be. You want to place the middle of the board on the lip and get the fins out over the lip, that way the board will slide across the lip without resistance.
3. From there, it's a case of holding on for dear life and hoping that you ride out of it. On your way down, put your weight on your front foot to keep the tail from digging in. At the bottom of the wave, bend your knees and let the wave pick you back up. From there, all you need to do is torque your body in a direction and the board will follow.