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.
Also, while practice in very important, remember that practice doesn’t make perfect. It’s “PERFECT practice makes perfect.” More frequent practice shooting fewer rounds, but concentrating hard on what you’re doing, will be more productive than less frequent, higher round count practice.
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.
With regard to using the sights in defensive shooting, as Clint Smith wrote in the January/February 2008
American Handgunner:
"It's alway argued that in a fight shooters will not look at their sights. I strongly agree -- if no one has ever taught them otherwise. To say that people don't, or won't, look at their sights is wrong. People have, they will in the future, and they'll hit the...target too. The correct alignment of the sights is a learnable skill. Is a textbook perfect sight picture available in every fight? Of course not....In fairness, the sights are only part of the issue -- the jerked on trigger doesn't improve anything."
Even when one has been taught to look at the sights, how much has he actually practiced quickly seeing the adequate sight picture and acting reflexively, without conscious thought, on the rough sight picture? As another trainer, Bennie Cooley, once told me, "It's not that I shoot quicker than you do. It's that I see quicker." One can learn to use the sights very, very quickly. And of course, at very close distances, point shooting makes sense.
In any case, whether you hold the gun with one hand or two, and whether you use the sights or point shooting techniques to direct the muzzle of the gun in line with the particular part of the target you want to hit, if you don't have trigger control, your muzzle will not be in line with the part of the target you want to hit when the bullet leaves the barrel of your gun -- and you will miss. But if you have controlled the trigger properly, you will hit.
And for some instructions on proper grip, check out
http://www.youtube.com/watch?v=oQgLmQl1zDw (in fact, everything that shootingcoach has on YouTube is worthwhile.)
Finally, some instruction is always a good idea. I try to take classes from time to time; and I always learn something new.
Think: front sight, press, surprise.
