The GRE requires personal identification along with your registration confirmation card. Carefully organize these items in a folder or envelope before leaving for the testing center so you're not scrambling upon arrival. In order to be an acceptable form of original identification your ID must have the following: a valid date, a picture, your signature and your full name as it appears on the confirmation ticket. In other words, if your ID says your name is James A. Smith but you registered for the GRE as Jimmy Smith, you will not be able to take the test. The only way to change the confirmation ticket to match a different name on your ID is to reregister and wait several more months.
The temperature of your testing center will likely be cool, so wear layered items to accommodate any personal climate fluctuations. For example, wear a T-shirt, long pants and a zip-up sweatshirt or cardigan that is easily removed if you become warm. Err on the side of comfort; the only way your GRE score reflects your clothing is if you're uncomfortable and distracted while taking the test. Note that the testing monitors can inspect any personal accessories or clothing as necessary.
Map out the route to the testing center in advance and practice driving there at the same time of day your test is scheduled. For example, if your test is at 9 a.m. on a Monday, drive there during another weekday and see how long it takes you. Map out multiple routes in case construction blocks off a road and plan on arriving 30 minutes early so you don't feel rushed. Note the location of parking and whether the parking is free, pay-per-hour, ticketed, or paid for by some other method.
Familiarize yourself with the rules and regulations of the GRE testing center to prevent any issues on testing day. For example, you may not take phones, drinks, calculators or food into the testing center without special accommodations that require permission months prior to the testing date. The computerized test will designate certain breaks during the test which require you to raise your hand and receive permission from the monitor. Failing to follow these policies to the letter means your testing results could be voided.