I have a coffee maker in the classroom. The first day of the class I make a pot of coffee and encourage anyone who would like a cup to enjoy. I then let them know if they would like to continue to have coffee it is up to them to supply the coffee. I let them know I will supply the other necessities for coffee(cups,cream,sugar). I also let them know if you finish the pot you refill the pot. This gives the students some responsibility,it promotes teamwork to keep the pot filled and the smell of coffee brewing is comforting to most.