Maybe obvious, but if you are dealing with any wobble, let the shot go when the sight picture is headed (back to) the bull. It obviously takes a millisecond for your brain/eye/finger to react and the shot to go off. Oh yea,... lots of practice never hurts either.
Of the 3 places of consentration for open sight pistol..the front sight counted more than the others.
Allen, what type of airgun are you shooting?
Allan,When shooting a springer especially, I find that maintaining mental focus on the target until well after the shot helps a lot. This implies maintaining one's aim, hold and pressure on the trigger, until you see the target react (or dirt splash near it). If no pellet strike is obvious, then hold that concentration until you hear the projectile impact whatever it struck.