In this stance you would assume the opposite postition of your normal stance. Therefore, if you were REGULAR you would have your right foot foward instead of your left, and if you were GOOFY you would have your left foot foward instead of your right.

You ussually don't use switch stance until you have reached a supreme level in your normal stance (regular, goofy). Then you can re-learn all the tricks you have already leared. Then you could do something like a, "switch kickflip", or a, "switch ollie".