I used the Sport Ed model with each team member assigned a 'duty' for the team - ie - captain, co-captain, equipment manager, sportsmanship, spirit, warm up/drill sergeant), small groups/teams with one team acting as student refs (rotating every @10 minutes, building relationships between students in the classroom was a priority as was letting students be responsible for themselves and their team (sportsmanship, equipment, activity set up and clean up, drills and warm ups)