Are you talking about school tests or are you talking about the psychological quizzes that you can find on this site?
If it is school, the only thing that helps me is adequate preparation reading the course material on time and attending lectures. I also set aside a big pocket of time for review.
Most important for me is getting adequate sleep and eating a healthy low carb high protein meal a couple hours before the test.
If I do all that I try the best I can and accept the outcome.