Use words from the 200 word list, as well as unfamiliar words encountered in your study and reading, to make flash cards that incorporate definitions, synonyms, and antonyms. Remember to include words that can have different meanings depending on their part of speech. (For example, 'appropriate' means different things if it's used as an adjective or verb) The GRE loves to use these kind of trick words!
Set a weekly or daily goal of learning new vocab words. If you give yourself two months to study before he exam, you need to learn about 4 new words a day. Practice doing antonym and analogy questions in 30 seconds or less, and sentence completions in 45 seconds or less. That way you can buy more time to do the reading comprehension.
When you learn words, make sure to learn the meanings of the roots as well. For example, if you learn that 'osseous' means made of bone, you can deduce what 'ossify' means by knowing that 'oss' denotes bone.
If a word has more than one meaning, and the meanings are very different, make a separate flash cards for the various definitions. The GRE can make vocab questions hard by using uncommon definitions of common words.
Practice writing your own analogy, antonym, and completion questions. Writing your own GRE questions will help you think like a test maker. Examine the wrong answer choices that accompany practice questions and take note of the patterns. Often, the antonyms will have a wrong answer choice that is a synonym of the word.
The best thing you can do to prepare for the GRE vocab questions is practice consistently everyday. Set aside an hour on weekdays and a few hours on weekends to study new words and tackle a few reading passages. Do some math problems in between to avoid burn out. Get a GRE verbal study guide that comes with practice test CDs so you get comfortable with the computer adaptive test (CAT) format.