Seriously - Hockey: start dicking around at about 8-0, don't run it up. Try to emulate one of your favorite players moves just to see what you can do then pass the puck off to someone else.
Baseball: After around 8-0 stop stealing, bunting, etc., after about 12-0 run base to base. It sucks seeing an easy triple turned into a single but there's no reason to jam it in their ass.
Basketball: Stop running plays, burn the clock down on every possession, start havin fun. Don't be putting up 3-balls when you're up by 30.