stop breathing at halfway out
Since there is no way to measure "half a breath" consistently, we do not teach this; rather based on your natural breathing habits, the pause before your next breath is the MOST consistent of any respiratory pauses.
The Six Steps of firing the shot (Appleseed Marksmanship Training):
1. Sight ALIGNMENT.
If you're using iron sights, line up the sights. If you're using a scope, this is already done for you.
2. Sight PICTURE.
Make sure your sights are aimed where you want the bullet to impact the target.
3. Respiratory PAUSE
Just like your natural respiratory pause before you take another breath; except you will hold your breath instead of taking another breath.
4a. Focus your EYE on the FRONT SIGHT
Simple as that; make sure that your eye is focused on your sight/crosshairs, and not some other area of the sight/reticle.
4b. Focus your MIND on KEEPING the front sight on the TARGET
If you have your eye focused on the front sight/scope reticle, but it's not on the target, how are you helping yourself? Keep the sights on the target, all the time.
5. SQUEEZE the trigger
Just like squeezing a lemon; it's not a jerk or a pull; you're just slowly pressing the trigger back till it goes click.
6. Follow Through:
-Hold the trigger back (if you don't, you can impart motion on the rifle; therefore decreasing accuracy)
-Take a “MENTAL SNAPSHOT” of where the front sight was when the round went off.
You're calling your shots on this one. If you know where that front sight/reticle was pointed when you squeezed that trigger, that's where the round should be.
Also you should consider an Appleseed Marksmanship Clinic
I am an Instructor for them, and I have got to say, it's well worth the few bucks you spend to learn some excellent marksmanship training that would cost you $500+ elsewhere.
appleseedinfo.org