One of the most useful tools in the ongoing struggle to shoot good is dry firing--aiming and snapping the trigger with no ammo in the chamber. Dry firing had no greater champion than the late Creighton Audette, a gunsmith, a friend of mine, and a high-power competitor who was good enough to shoot on the Palma Team, and coach it. "Recoil," he said, "is a form of distraction." He believed that any serious shooter should do far more dry-firing than practice with live ammo. (Creighton also said "Everyone should have at least one gun the government doesn't know about," if you need any further proof of his wisdom.)
The Marine Corps used to start its marksmanship training with a solid week of nothing but "snapping in"--dry fire from the basic shooting positions--to show the maggots how to do things correctly before they got live ammo. Dry fire allows you to concentrate, without distraction, on the instant when the trigger lets go and the instant immediately afterward, when so much can go wrong.
Dry fire, however, is not for every firearm. It's OK to dry-fire most bolt-action rifles, but the practice can damage most .22s, just about all shotguns, and some handguns. If you are in doubt about its effect on your firearms, consult your gunsmith.
It's invaluable, costs nothing, won't give you a flinch, and makes no noise. Dry-fire a lot and you will shoot better. As Ed Zern said, "Keep your powder, your martinis, your trout flies, and your fire, dry."