"Be consistent. This is actually the most important key to effective parenting. Inconsistency is completely ineffective. Your son is on a play date, and he hits another child. Reprimand him and explain that if he hits again, you'll take him home. If he does it again, pack him up and leave -- even if it's inconvenient. It's never easy to stick to your guns with a threat or a punishment, but the second that you give in, you lose all credibility."
~Richard Carlson, Ph.D.
The Don't Sweat Guide for Parents