Buy a spritzer bottle from a garden center or store and with the permission of the people in your class - spritz their legs during the part where you tell them to feel the cool water on their legs as they bike through the water. It is soooo refreshing - I even brought a small stuffed bear to use for the bear hunt routine. It makes the class fun and revitalizes the hot, sweaty cyclists!!
Keep adding those patterns - I'm new to spinning but it's a nice change!