in the army they stress over and over and over again to control your breathing. That's where I really learned to control it. It's true, you will shoot 100% better if you control it. Plus, when deer hunting, your adrenaline is pumping so to get your heart rate under control AND your breathing under control can sometimes be a task in itself.
...I am not skilled to understand, what God has willed, what God has planned, I only know at His right hand, stands One who is my Savior....