Make sure that your rules and expectations for the classroom are understood by every student so that they all can follow them correctly. 

Have consistent consequences for behaviors and make sure that students are aware of the levels of them. Ex. Don't send somebody to the principal for running in the classroom once.

If you say you're going to give a consequence, THEN DO IT. In addition, make sure that your consequences are actually something that you can follow through on when you say it or students will learn what you will and won't actually do. 

You are responsible for setting the boundaries/ rules and enforcing them, so make sure you keep up your end of the deal! I would also like to add here that you need to take accountability if you mess up! If you are teaching your students to be responsible and accountable for their actions, then you should model what that looks like for them. 

Tieing back into the last point, if you can do it, they can too. Make sure that they know that they are the only person accountable for their actions so they can't play the blame game or snitch on other students when they get in trouble.