This from another thread, but I'd be interested in feedback on the approach and on the concept.
Another instructor at our hill has a "pop" in her turns - the dreaded up move. Trying for a long time to get rid of it, but most attempts to eliminate the move created stiff and uncomfortable skiing.
I suggested to her that she shouldn't try to get rid of something, but to do something else. Don't think of the negative thing, think of something positive.
An examiner told me recently that one of the key movements they look for in candidates is that the extension shouldn't happen until after the edge change. So I thought, perhaps the key for her would be not to stop the "up" move (or extension) but to change when it happens. To tip her skis - change edges first - then to extend. In this case the extension will not be an "up" move, but a diagonal across-the-skis movement down the hill. A simple timing change. Don't get rid of the extension, but do it after the edge change.
I never coach other instructors, I'm not a trainer, but we went out on the hill and I coached her. It worked. She was thrilled and told me it was the most effective coaching she thought she'd had in a long time. We'll see what focusing on this one simple thing does for her skiing after a few days.
A (hopefully) positive change in her skiing, by a positive focus. Stop thinking about what you should NOT do, but think about what you SHOULD do.