If you are on deck, tell the runner coming home whether he needs to slide or not. Never chastise another player where others can hear you. If somebody makes a mental error, they already know they made a mistake. Don't remind them. If your fortunate enough to play on a Good Team, Treat it like a privilege.
Somebody has to bat last.
If you invite a substitute out to fill a vacant spot, treat them like a royal guest. Never under estimate another team, its slow pitch. What comes around will definitely goes around. If you're winning big, don't rub it in. Save the beer drinking until after the game.