Aiming a rifle has nothing in common with aiming a shot in pool.
First, a rifle has a rear sight, a front sight, and there is a target. You can touch these. You can feel these. I've yet to touch or feel any form of sights on a cue and there is no "Hit here" sign on the OB either.
Second, there are times in aiming a rifle, the muzzle is not pointed to where you want to hit. Distance and wind come into play when aiming a rifle also the weight of the bullet and the load of the round.
You may the same type of breathing methods used in shooting in making a shot in pool, but that's it.
I get so tired of the ole golf and pool comparisons. Two different sports with two different goals. A drive in golf has nothing to do with a pool shot. IF anything, putting is closer to shot making in pool, trying to get a ball in the hole the first time.
Thing is, in golf, you got one ball and one hole at a time, plus you do not have to get shape for your next tee shot. Ain't so in pool. You have to use the CB to make a OB and then get position for the next shot. Ain't nothing in playing golf that equals this.
There is nothing a player can do to increase a shots margin of error. To imply otherwise shows a lack of understanding of the geometry of a shot. A shots margin of error is determined by the pocket opening, OB distance from the pocket and OB angle into the pocket. How much of this area that can be used is determined by the OB/CB angle.
As for hitting center pocket-
http://forums.azbilliards.com/showthread.php?t=272971
And just food for thought
http://forums.azbilliards.com/showthread.php?t=272973