I particularly like the idea of having a discussion with the class to create a set of rules for the management of the class. This way, students' buy in to the process will be achieved and students will be fully aware of what the expectations of the teacher and the class members will be. When any disruptions occurs, the agreed rules can be reviewed and used as a guide by the class. It will be even better if all classes participates in this activity. It helps to build an understanding that this is what we expect of each other.