The hardest part for me with squats is usually reps. I get depressed about how many I am about to have to do and psych myself down. Heavy singles, doubles, or triples I can usually work myself into a rage and unrack the bar with purpose. The way I unrack determines how the set will go. If I unrack with power, it goes well, if I unrack gently, I fall short.
Anastas Dimitar Martin