One way, is to pretend your front sight is on a lever, Your trigger is on the other end of the lever. What you want to do is use your trigger to slide your front sight to the real of the pistol/revolver.
If you concentrate on both the trigger and front sight, it actually looks like you are sliding the front sight to the rear of the pistol/revolver.
Of course we know its not coming back, but what is happening, you are concentration on the front sight to see if it moves. Doing so makes the front sight Cear and Sharp, makes it look bigger, giving the illusion that it is really sliding back.
Its hard to beat hours and hours of dry firing,
Another ideal is to turn the target around so you are looking at the back.
Put the front sight into the center of the clear, white square. You dont have anything else to look at so you look at your front sight.
Try that, the after shooting, take the target down and look at the bull. You'd be supprised how tight the group is.
While doing this, and dryfiring, remember the first ideal, keep trying to slide the front sight back with the trigger.