I have 4 drafts of each exam and the student's don't know which copy they have. I explain this on the first day along with the rules reguarding test day regulations. I have the students clear their desk of all irrevelent material and cell phones are never allowed to be taken out during class. The student's may check their phone during the break. I have had this problem in my class and that is how I came up with my test taking rules and why I also have 4 drafts of each exam.

I find that by using my own life situations to inhance the importance of the lesson really drives home the message with the students. It also lets them know I am human and that everyone, including me, will make a mistake. The trick is to learn from it and move on. I don't expect perfection, I expect them to try their best and fix whatever they may mess up.