Do not prepare for an exam by?

Answer 1

It is best NOT to stay up late the night before a test in order to cram. It is best NOT to study in a way that is unconnected to the test. That is, if the test is written, you should study by practicing what you will write. If the test is oral, you should practice saying what you will say. (Some studies have shown that a student has best results if s/he takes the test in the same mental state as when she or he studied the material.)