I've seen people spend far more effort trying to cheat on tests than if they'd simply studied the material.
I remember one method I would use is to simply memorize thousands of multiple choice questions from the test bank. That way when you took the exam, you would already be familiar with the question on the exam and how to solve it.
He laughed and said because the students needed all the help they could get. Years later I realized he probably was trolling me.
That's not cheating per se, though, just studying with previous exam questions as practice material. I'd wager all students that can access old tests do that.