Always know where everyone is and where the teacher is. Also pay attention to who is watching you, because you don't want 20 people watching you or ratting on you.

A tip is don't keep looking down, but don't keep your eyes down. If you are like with your phone like me then, you should only do it when nobody is looking and only for 2 seconds.

And don't make it obvious or blow your cover. Because once you get caught you will be watched by the teacher and everyone who is a hatter.