How do I use a real GRE exam as a practice test?

You can take the real GRE knowing that most programs won't hold a lower score against you if you also send a higher one, and if you're concerned, ScoreSelect lets you choose which scores schools see. A strong performance becomes your official score; a weak one stays hidden. Keep in mind you can test only five times in any 12-month period, at least 21 days apart, and each attempt costs the full $249 fee, so be strategic about it.