If you play poorly one day, forget it.
If you play poorly the next time out, review your fundamentals of grip, stance, aim and ball position. Most mistakes are made before the club is swung.
If you play poorly for a third time in a row, go see your professional.

Harvey Penick's Little Red Book: Lessons And Teachings From A Lifetime In Golf (ed. Simon and Schuster, 2012) - ISBN: 9781451683219