You should have 3-5 rules that the students know about. These are the rules that, when broken, are subject to the consequence scheme outlined above. Try allowing the class to suggest the ground rules: have a class discussion and write ideas, it makes the class feel they are listened to and that you care about their opinions and input while also setting some groundwork that they will feel loyal to because they've made it. Act as a mediator to make sure that the rules decided upon are appropriate. Some may be, for instance, be quiet when the teacher is talking, respect each other, and finish the homework and classwork.