My best finishes on the LPGA Tour have come when I've played thinking about one thing: keeping my head steady. I know it moves laterally a bit, but trying to keep it in place helps me make a smooth swing -- and it gives me the best chance of hitting the ball flush. Think about it: If you make a wild swing, there's no way you're keeping your head still. With the driver, I set up with my head behind the ball and try to make sure it doesn't move ahead of it. If you look at the best players in the world, their head movement is so quiet.
I really think this is crucial to hitting the narrowest fairways. Try it if you need more control off the tee.