THE WHISTLE!--used in HS classrooms to gain attention. Nothing like the sound revirberating off of walls to get attention!!!! Not a good idea in lower grades. Too upsetting.
THE TROUBLE MAKER--if at all possible, make him (usually works better with boys than girls) my best friend. Paper passer outer, door closer, etc. It tends to give them the attention they are working so hard to achieve.
ARGUMENTS--I never try to win an argument. I found out a long, long time ago that you can not win. I either ignore the subject that I am trying to be pulled into or change the subject completely.
CALLING FOR REINFORCEMENT-- I have found that if you have the need, call for help. I had a 8th grade class where the teacher had been out for several days and I was the third sub they had. I knew that they were not upset with me, they were missing the regular teacher. The class had decided that they were not doing anything and had become quite out of hand. I called for reinforcements from the office and within 20 seconds I had four other teachers at my door. The principal thanked me for calling instead of getting "upset" and having a bad situation turn ugly.
WATCH OTHER TEACHERS---If I can, I will use my prep time to sit in the back of a classroom (with permission of the teacher) to pick up techniques or ideas. Most teachers are grateful for the extra body in the class.
I have found that the best subs are the ones that share ideas.
Been there, done that, doing it still......