I'm a big proponent of good professional training. Among other things, there is really no good substitute for a qualified instructor watching what you are doing and coaching you based on what he sees. Remember that practice doesn't make perfect. Only perfect practice makes perfect.
Practice also makes permanent. If you keep practicing doing something wrong, you will become an expert at doing it wrong. So some good training shows you what to practice and how to practice it. It thus helps you avoid bad habits which later on can be an awful hassle to try to correct.
The first principle of accurate shooting is trigger control: a smooth, press straight back on the trigger with only the trigger finger moving. Maintain your focus on the front sight as you press the trigger, increasing pressure on the trigger until the shot breaks. Don't try to predict exactly when the gun will go off nor try to cause the shot to break at a particular moment. This is what Jeff Cooper called the "surprise break."
By keeping focus on the front sight and increasing pressure on the trigger until the gun essentially shoots itself, you don’t anticipate the shot breaking. But if you try to make the shot break at that one instant in time when everything seem steady and aligned, you usually wind up jerking the trigger. Of course the gun will wobble some on the target. Try not to worry about the wobble and don’t worry about trying to keep the sight aligned on a single point. Just let the front sight be somewhere in a small, imaginary box in the center of the target.
Also, work on follow through. Be aware of where on the target the front sight is as the shot breaks and watch the front sight lift off that point as the gun recoils – all the time maintaining focus on the front sight.
Practice deliberately, making every shot count, to program good habits and muscle memory. Dry practice is very helpful. You just want to triple check that the gun is not loaded, and there should be no ammunition anywhere around. When engaging in dry practice, religiously follow Rule 2 - Never Let Your Muzzle Cover Anything You Are Not Willing To Destroy." As you dry fire, you want to reach the point where you can't see any movement of the sight as the sear releases and the hammer falls.
Think: front sight, press, surprise.