There are two types of shooting practice. Marksmanship focuses on hitting the center of the target. Defensive shooting focuses on hitting the target to stop the threat. What does this mean? Think about 3 shots in a two inch group in 10 seconds versus 5 shots in a 6 inch group in 5 seconds. Which is more likely to stop the threat?
Marksmanship is great, and I believe in going to the range and working on fundamentals. However, once you know you can hit your target, consistently, then what? Do you carry for self defense? If so, you should practice like you will shoot. When you are startled, what do you do? Think about the last time you were scared? Did you square to the threat? Did you go into a little bit of a crouch? Can you draw and present your gun in one smooth motion, bringing it up to your head, maybe sighting insensitively versus with the sights? Can you get off several shots into a target without trying to get them all through the x and not use your sights?
Do you keep your gun in a high ready until you are ready to shoot, then return to high ready? In a real situation if your gun is in close to you, and pointed slightly down, it is easier for you to maintain control of, minimizing the risk it could be taken from you.
Think about how you will react in a real life situation, and practice that way. Think, plan, practice...