Since you absorbed the impact with your knees, you should now be able to simply extend your legs to help push off the extension. Once you are about to land be sure to have a good center of balance. It is really easy to be too far forward or too far back. Spot your landing and stomp your board back down to the ramp. If your browser supports Javascript and Flash 5 you are missing out on a lot of features.
Vans shoes have some of the most grippy soles around.
They keep me on my board like a fly on fly paper.