I agree with Jerry about not keeping your cheek on the stock, and especially your foot placement. Try taking just a little more time to take a step backwards with the right foot, or forward with the left, to give you more "room" to swing right without "winding up". That little extra time taken to do that can pay great dividends. If it takes too much time and you can't get the shot off, well, it's better to not take the shot anyway than to miss 80+% of those shots.
Try also to work on cutting back on the total length of the swing. I've learned that the more your hands are involved in the shot, as in longer swings, the greater the chance of getting off line or trying to "measure the lead". I learned this from Bill McGuire, a very successful pro shooter. I insert the gun, nearly always, on or just ahead of the bird and then, with a very short move, pull away and shoot. Let your eyes do the work for you. They are much more dependable than your muscles that you use to swing the gun. There is just so much swing that our bodies are capable of before our muscles "wind up" and we lift our head or drop the shoulder.
People watching me shoot sometimes comment on how little muzzle movement I have, at times calling it "spot shooting". It's not spot shooting at all, there is just a very short and quick move to establish lead, sometimes almost unnoticeable to bystanders.
Stan
