Maybe you could make them cookies or other baked goods, that would leave an impression more than us simply "being quiet" and "cheering for our own team." I think we do well when we stay after, meet the guys, sometimes even take pictures with them with our signs or costumes that we used to playfully mock them. We've met a lot of opposing teams and players and I don't even remember one being rude or acting hurt by what we did to make the game more exciting and interesting.