Trigger “management” is one of the most critical elements of accurate shooting whether it’s a handgun, AR, crossbow, or the release of a compound.  As a hunter who used to shoot a recurve instinctively, the release of the string with my fingers was equally important to accurate, consistent shot placement.

Surprise or No?

Although “pulling a trigger” seems like a simple act, it greatly affects accuracy.  For rifle shooters employing the off-hand position, the best shot occurs when the sight is squarely on the target.  However, as the sight picture moves due to unsteady report, the time of the shot is difficult to predict.

Target Panic

If you are an archer who releases with fingers, target panic can be a maddening situation. Personally, I’ve been through this problem in which your mind refuses to allow the sight pin to settle on the target before releasing.  A release aid solves this problem because you don’t have the certainty of release like with fingers.  Rifle shooters may experience a similar situation when shooting three-shot groups.  If the first two rounds print like a clover leaf, you may have difficulty squeezing off that third shot.  Mentally, you think you are squeezing the trigger, yet the rifle doesn’t fire.

Develop Trigger Habits

Archers often begin their annual practice regimens by shooting with their eye’s closed.  In this way, they can concentrate completely on form including squeezing the release aide.  After good habits are developed, the aiming and grouping process begins.  Firearm users can hone their skills by dry firing their gun.  This works best with a buddy that loads or not, out of your sight.  In this way, you must concentrate completely on the mechanics of the shot.  This post from the Field & Stream website looks at traditional thoughts on trigger squeeze with advice from a professional:

Let’s start this one off with a little animal-husbandry humor.
A farmer and his wife were having the parson over for Sunday dinner. At the same time, the farmer had rented a bull to stand stud to his two cows, a brown cow and a white one. He detailed his son to go out to the barn and report on the proceedings should anything romantic happen while dinner was in progress.
The parson arrived and the meal was served. But almost immediately, the kid came bursting into the dining room and yelled, “Pa! Pa! The bull’s f—ing the brown cow!”

http://www.fieldandstream.com/surprise-surprise-how-to-squeeze-trigger