Here's how to use Highlighter magic markers to study textbooks. Make Sure You Own The Textbook: Buy a used or new textbook that you don't need to sell or give back. If the text book is already marked with a certain color highlighter, choose a different, darker color for your marking. Don't buy textbooks that are already marked with dark (red or blue) colored highlighters. Highlight Only The Important Parts: Highlight only what you need to learn for the tests. If you highlight too much of the book, the markings will be useless because of the excess of information. Only highlight specific terms and their definitions, as well as items that the professor says are important or will be on the test. Use Different Colors: If you are highlighting terms for a paper, but not the test, use a different color highlighter. Also, you might wish to highlight key concepts in one color and definitions in another.