Corked is basically when you drop the shoulder in the way you are spinning, ie left direction spin, left shoulder, and you end up looking at the ground. Flat spin is the opposite, you drop your right shoulder if you are spinning left. But, I can't do them either. people tell me to jump and drop the shoulder, start to spin, then bring your feet up and hang on, and spot your landing. I can almost do it on a diving board, but haven't treid it on skis.