Another tip I just thought about is to set yourself and the rifle so it is naturally pointed at the target. Any time you have to muscle the rifle onto the target, you are building in error. Set yourself and the rifle up and look at the target. Is the sights or the cross hairs on the target and reasonably centered? if not, adjust yourself and the rifle so it is. It won't be perfectly centered but the less you have to force the sights on the target, the more accurate you will be over and over again.