How to Survive The Day as a SUBSTITUTE Teacher….. 
1) Smile when you walk into the classroom.
2) Introduce yourself to the students as their teacher for the day. If you say you’re the substitute they might enter party mode instantaneously.
3) Avoid drinking too much!! You never know when you’re next bathroom break will be!
4) If it isn’t written down for you anywhere, don’t let the students do what they’re asking. (They are most likely not allowed to use their phones in class!)
5) Pick a helpful student. You never know when a teacher’s pet might just come in handy.
6) Never let them see you sweat!! Be clear about your rules and expectations.
7) If you need a few minutes of sanity, have the students read quietly.
8) Be prepared to improvise! You never know, you might end up having to put on a show by the time 3 o clock rolls around!
9) Introduce yourself and interact with other teachers, if all things go well you might become part of their staff.
10) Lastly, remember why you are there (hopefully to get a permanent job). Be professional and do your best!