I'm on duty! Today I SUB!

OMG! The regular teacher couldn't come today and asked me to stay with her/his class.
WHAT DO I DO???

First of all you need to be extra patient and kind with the students.

Be prepared to listen and deal with comparisons: "My teacher doesn't do this in the way you're doing!"

When you listen to this, try to be nice. Tell the students that you're not their teacher, you're just doing a favor for her/him and that they should try to do on your way, because, maybe, it can be as fun as the other way.

You don't have to change your teaching, but you also shouldn't impose it. Try to make a balanced situation.

Sometimes the students freak out, you must be calm and don't yell at them.

Try to talk nicely and control them. Be strict, but don't be rude. If they don't change, focus on the students that are paying attention. There's always somebody interested on the subject. And then ask the other students to be, at least, quite.

Prepare the class. Arrive a little early to get updated, to know what they need to accomplish on that day. Avoid extra activities, musics or movies, because most of the times the class must go on. If you choose an extra activity they might get their schedule messed up.

Be natural, do your best!

After the class make a report to the regular teacher.

Hope it's helpful!