Everybody has pretty much covered mechanics, calming of the nerves, practice, etc. But one thing I might mention is keep the crosshairs on the target...almost like a follow through idea. I have seen many try and look over or around the gun/scope when squezzing on game...but you should be able to see the whole thing unfold through the scope...if not you are closing your eyes or dropping/swinging the barrel. Try a rest, tucking that gun in and looking through the scope at the target before and after you shoot. If you use iron sights well it is a bit tougher but still possible...picture the bullseye and watch that bullseye through all parts of the shot. The slightest pressure up or down can make the difference. Not only that some people think the crosshairs are where they are suppose to be but really forget to see the + mark the spot and shoot off either the lateral or horizontal line...which results in misses. Put the + where you want the bullet to go, remember your mechanics and you'll be fine.