Folks tend to focus on breathing and trigger, but for me, pulse bump at 600 yards plus is a real issue. Learning to employ a natural point of aim is huge as well, because unless you are just an absolute ace, shooting off the natural aim point will cause muscle induced error.
At 600 yards and over you really have to learn to judge that brief interval where the wind is falling and your heart is in between beats.
“but for me, pulse bump at 600 yards plus is a real issue”
It’s frustrating that holding your breath amplifies pulse bump.
It helps to slow the rate just a little, but enough.