Create and study flash cards featuring GRE vocabulary words. Write the word on the front of the flash card and the definition on the back, and keep these flash cards on you at all times. That way, when you're waiting for a doctor's appointment or for a class to start, you can pull them out and study. Knowing these words will help you tackle the GRE's verbal section, which includes analogies, antonyms and sentence completion questions.
Read sample passages to assess your reading comprehension skills. Pull a paragraph out of a book, and give yourself one minute to read it. Then, close the book and write down the key concepts from the paragraph. Focus on understanding the relationships among ideas in the paragraph and the relationship of the author with the topic or audience. The more quickly you can read and assess paragraphs when you take the GRE, the more time you will have to answer the reading comprehension questions.
Study basic math problems. According to GRE Guide, the GRE math, or quantitative, section includes four types of problems --- arithmetic, algebra, geometry and data analysis. Practice basic algebraic equations, and remind yourself how to calculate percentages, set up equations to solve a word problem and calculate the Pythagorean theorem.
Practice writing to prepare for the analytical writing section. Issue task topics challenge students to express their position on the topic using examples. The Educational Testing Service lists general issue topics that you can review. Practice building an outline that you can refer to as you write. Write freely for 45 minutes, setting aside time for outlining and revising. Also, review argument task topics on the GRE website, and practice writing those for 30 minutes. In these essays, focus on explaining how well reasoned you find the argument provided.
Take sample tests online. The Educational Testing Service website offers sample questions, which allow you to gauge your level of preparation for the test. If you find yourself struggling with a specific type of question, you can go back to your study materials to improve your knowledge in that area.