For me your ability to handle disruptive students begins with day one, before you ever get to the bad days. You need to if at all possible build connections with your students. Especially with those high risk students who are having a difficult time in school. Often their disruptive behaviour comes from other struggles in the class either academically or socially. The better the connection you have with them the more likely you will be able to manage the behaviour. Not always perfect but a good start.