Finish what you start. Do not quit a game you are losing. A game you walked out on is worth nothing to anybody, and it goes on your record — see Disconnects & Quits.
Talk your talk, keep it human. Trash talk is part of the game. Keep it about basketball, keep it in the league's channels, and keep it the kind of thing two adults laugh about later.
Answer the office. When the commissioner asks you about a game, respond. Silence is not a defense and it is not a strategy.