For our purposes, a mantra the last thing that you mentally say to yourself before you call for the target. This mental cue gives you a point of focus.
If you missed your last shot or if you have just run 24 straight and the pressure is on to break the last target, I don't want you thinking anything negative. Human nature is to tell ourselves, "whatever you do, don't miss". Your mind starts dwelling on missing, which is the opposite outcome you want.
A mantra helps you stay focused on the task for every shot. Below are some examples.
Examples of a mantra:
"See the target"
"Hit the target"
"See the target hit, hit the target"
I don't care if you use one of these or make up your own. You need to commit to something specific and make it part of your pre-shot routine.