Bring along tablecloths in your favorite school's colors and crisscross them on the buffet site, whether it really is a tail gate or a portable table or card table. Buy the plastic plates and flatware in colors to match or coordinate. Gather the serving pieces and utensils well in advance. Have the forks and knives wrapped in napkins for easy access. Mums are plentiful now and come in many colors to complement the spread.
Baskets are easy to line with napkins in team colors and decorate with fresh flowers.
Fill with bread, jars of mustard, fruit, scones, and the plates and napkin-wrapped flatware. But don't stop there. If you have been friendly for a while, bring memorabilia from other football games you have gone to together, college days souvenirs, a football to throw around after lunch, school pennants, t-shirts to pull on over sweaters for the diehard fans, and programs, if available. For comfort bring blankets, folding chairs, and large plastic trash bags for quick clean up. Remember to keep cold food cold and hot food hot to prevent contamination.