Are you talking about standers, kneelers or freestyle, or all of them?
It's a big factor in FT to get the rig to fit you, not you to fit the rig. If it's a seated shot, get into a comfortable position to address the target then get someone else to offer the gun up to your position, and see where it doesn't fit. That's a start.
For seated and kneeling shots, as you breathe in, the muzzle dips, and as you breathe out it comes up again. As you want to take the shot after exhaling (partly or fully) then your rest position will be with the muzzle at its highest point in the cycle. Make sure you are using the least possible amount of muscle power and the maximimum amount of support from your bones.
Breathe out and count to four. If you haven't taken the shot by four, breathe again and count again.