After a few years off, I'm getting an interest in golf again. My main problem, after getting a few basic pointers correcting my stance and backswing from a clubfitter I was working with to find the right driver, is a tendency to back away from the ball with my upper body at impact, causing me to hit the ball thin, top it or whiff it. I know I'm doing it, and correct it on the next swing, but that's only an option at the driving range, not on the course. The only advice the clubfitter could give was "don't do that".
Is there a common drill that can help reduce this tendency and integrate it into my muscle memory? It seems to only happen with woods, sometimes my hybrid, never on irons, so I'm thinking it's caused by the longer shaft length and the desire for distance making me put my back into it too much.