I take up the attitude that if I mess up it is because I failed to practice sufficiently. As hard as it is it kind of allows me to release myself of accountability over my performance during the match. If or when I fail I blame my former self for not practicing enough and that also motivates me not not drag myself down While practicing for future matches.
At smaller matchesI won't change my plan after 5 minutes is up. Doesn't matter if I'm the last shooter in the squad. Larger matches, that buffer is even larger, by the time I get to the stage in a larger match it should be nothing but review.