Here are some of my favorite final exam tips and tricks:
1. Bring in a pocket shoe organizer and make all students turn their phones off and place them in a pocket prior to the exam.
2. Create simple "blockers" by stapling two cheap pocket folders together (I get mine in the summer when Staples and Office Max have sales where they are only a penny, they usually last all year).
3. Sit BEHIND your students when they are taking their exams. They won't be able to see if you're watching them or not unless they turn around (which would be far too obvious), so anyone who intended to cheat will be horribly paranoid the whole time and hopefully won't risk it.
4. Have something for students to do if they finish early. I usually create a end of the year survey that they can complete. They give me some valuable feedback but are easy enough to complete that most kids will do it. Another idea is a drawing competition. I randomly pick a student from the class, a place, and a verb and have them draw the funniest scene they can (school appropriate of course). I display them on the board after the test.
5. Give your students a proper goodbye! You have just spent a whole school year together (which is a long time in teenage years) - make sure your students know that you wish them luck in the future and that you enjoyed your year with them (even if they were pains in the butt at times and made you consider an early retirement).
Here are links to my Final Exam products and Study Guides if you need to save time this Final Exam season: