Great advice you have been given.
You are aniticipating the recoil, so your subconcience mind is changing your grip, or you are jerking the trigger.
If a lot of you shots (The following tips are for a right hander, if you are left handed, just reverse everthing) are going a little low/left, you are jerking the trigger. The most common cause of bad shots.
You need to slowly squeeze the trigger, not pull/jerk it, and make sure that you do it straight to the rear so as not so move the sights.
Place your trigger finger's on the trigger in the middle of the first pad.
When you are holding your sights on the target, you WILL have movement of the sights/target alignment. That is perfectly normal, everybody, and I mean even the best shooter in the world have it. Once you are holding on the target, keep it the best you can (your brain will try to center it) while you are concentrating on your trigger squeeze.
Dry fire very slowly and watch the sights closely to see if your trigger movement is moving the sights either up/down/left or right. Adjust your finger pad accordingly. Too little trigger finger will cause the barrel to move to the left, too much will move it to the right. If you have curved trigger, make sure your finger is in the middle so as not to cause up/down movement of the barrel when squeezing.
The most important part is that when you take your aim, your sights are aligned with the target, you start to put pressure on the trigger......
You momentarily see the perfect sight alignment in the middle of the target, you gently squeeze a 'little' more to get the shot off when the sights are in the middle.
This will cause your shots to go low/left and be a lot more off center than if you just trusted yourself and kept on slowly squeezing. By jerking, you made a 9 a 6 or worse.
An excerpt from www.bullseyepistol.com
(fundamentals section) goes for pistols or rifles.
1.Settle Into Your Aiming Area. The normal area of movement is readily apparent. If it happens to be larger or have abnormal characteristics and you are unable to reduce it to normal, accept it and proceed to fire. However, make every effort to hold the weapon motionless.
2.Find Sight Alignment. Your sight alignment must be exact and in such distinct focus that the bullseye becomes a blurred gray mass somewhere beyond the front sight.
3.Start Positive Squeeze. Be determined that once started, a positive, constant rate of squeeze is to be completed without interruption. Any hesitation, change of rate, doubt about results or loss of concentration must be avoided.
4.Concentrate on Sight Alignment. Any distraction warrants benching the weapon and starting over. Do not try to fire the shot if any controllable irregularity disturbs the existence of ideal conditions. Do not think of impending results at the target Any surprise shot within the aiming area with good sight alignment will be a good shot.
5.Try for a Surprise Break of the Shot. Your reflexes cannot act quickly enough to disturb sight alignment or a smooth, positive squeeze if the shot breaks as a surprise. Shots breaking in the aiming area with good sight alignment will form a group that represents the equivalent of your holding ability.
6.Additional Suggestions. It may be advantageous to rest or relax after three or four shots. Remember that you do not have to shoot before bringing your gun down to rest. When a shooter fatigues, runs short of breath or experiences difficulty in concentration, by all means he should lower his arm, relax, breathe deeply and try again. Some excellent slow fire shooters try two or three times before getting a shot fired. Do not expect ever to have a perfect sight picture. You can shoot groups only within your ability to hold. If you can hold within the ten ring, they should go there. With experience and practice your ability to hold will increase and your groups will consequently grow smaller. Sometime during the 6- 15 seconds required to fire a shot in slow fire, your arc of movement will be sustained at a minimum. The shot sequence should progress at such a rate as to attain a surprise break during this period. Example: If a shooter's minimum arc of movement is reached at about nine seconds he should train himself to break his shots in 8-10 seconds.
B. Timed and Rapid Fire Techniques:
Prior to firing any string of timed or rapid fire it is imperative that you mentally run through the sequence of the string itself. You must be psychologically as well as physically ready to fire at 25 yards. You will find that this prior determination will assist in your rhythm, squeeze, and recovery and ease any match pressure that you are subjected to at the time.
1.Timed Fire. Prepare your lungs by breathing deeply prior to firing and holding the breath with lungs approximately half full just as you align your sights. Make rhythm the prime object. Never vary your rhythm. Adjust your recovery so that you'll have your sights aligned in time for the shot to go, but do not wait for the perfect sight picture. If you maintain your rhythm and fail to get the sight alignment just right, you may get nines, but if you make the weapon fire just as the sight picture is perfect, you will get the axe.
2.Rapid Fire. Rapid fire is essentially the same as timed fire. You can improve your rapid fire by learning to fire the first shot within the first second after the target faces you. Immediate recovery of sight alignment and hold after each shot depends on perfection of uniform position and grip. Special attention to an uninterrupted, unchanging rate of squeeze will help develop for you, the coordinated start your squeeze before the sights become perfectly aligned. Make every effort to prevent extraneous thoughts, which may disturb rhythm and concentration.
3.Shot Sequence for Timed and Rapid Fire.
a.Find aiming area on edge of the target frame in line with your aiming area.
b.Settle into aiming area.
c.Find sight alignment. The front sight should settle naturally into alignment with the rear sight, vertically and horizontally. Concentrate on looking at the front sight.
d.Start positive squeeze on turn of target. If your position and grip are correct and you are concentrating on alignment of the sights a squeeze started at the turn of the target will give you a 10 every time.
e.Squeeze continuously. In rapid fire you must start your squeeze before you have perfect sight alignment. This does not mean that you subordinate sight alignment to squeeze. Start your squeeze as quickly as possible while continuously concentrating on and perfecting sight alignment. Sight alignment not a sight picture. Your natural aversion to not firing without correct sight alignment will delay your squeeze until the sights are aligned.
f.Recovery. Correct recovery with the sights approximately aligned in the aiming area is obtained only if your position and grip are correct.
g.Concentrate on sight alignment. Any time the shot breaks with good sight alignment, it will strike the target within your ability to hold.