When lining up the perfect sight picture, your focus is not on the target, not on the rear sights, but on the front sight. You want your rear sights to be slightly out of focus, you want the target to be slightly out of focus, and you want the front sight to be perfectly in focus. This sounds counterintuitive, but you want to place that perfectly focused front sight in the middle of that blob of a target in front of you. This will become more pronounced at distances, as you watch the target get more and more blurry. Many new shooters put all their focus on the target and place the blurry front sight in the middle of the crisp target. That's incorrect. Make sure that front sight is in focus and placed over the blurry target. A hard focus on the front sight will ensure placing consistent shots in the center of your target every time.