One of the major mistakes of many novice shooters is not knowing what practice makes good practice. You can go out and shoot at a target all day long but unless you are making changes to improve you may end up just developing habits and frustrating yourself. There are actions that can be taken to avoid this detrimental series of events.
Never try to shoot beyond your ability. There is a line between this and pushing your boundaries that is sometimes hard to see. The main thing is to keep your goals attainable. For example, I am currently trying to get my FAST drill below 15 seconds. I am currently shooting between 15.09 and 16.5 seconds, therefore making this a difficult yet attainable goal.
Figure out what you’re doing wrong and correct it. Don’t keep making the same mistake until you frustrate yourself and start making more. Pay close attention to what you and the gun do during each shot that may cause you to throw shots. Your ultimate goal should be to know where your shot went without looking at the target, but this takes time. First you have to get used to what a “good” shot feels like then you can start looking at what the “bad” shots are doing and identify that with the feeling (whether it be a physical or mental mess up) and eventually recognize that feeling when it happens.
Stick to proven drills. The drills you find at, for example, pistol-training.com are there for a reason. Shooting at a hole in paper will only get you so far. The drills are not only beneficial to your shooting but also provide you with quantifiable feedback and allow you to track your progress.
Take a class if you haven’t already. A basic handgun course never hurt anybody. I had been shooting shotguns for years and handguns for a few months when I took Insight’s Basic Handgun course last February. It’s not about what you do or don’t know, it’s about having someone give you a proven method rather than collecting information from the guys at the range. It also gives you the opportunity to have someone knowledgeable watch you shoot and provide you with feedback.
The only real practice is good practice. It’s far more difficult to break bad habits than it is to take the time and necessary steps to build good ones to begin with.