Test day needs to be given the weight it deserves.  While you can retake the test over and over until you do what you think is the best you can do, if you master it the first time you will save yourself a lot of time and at US$250 a pop, a lot of money.

Time is of the essence.

Once you have decided that you are properly prepared to attempt the test, you need to schedule it.   That very decision can help or hurt your score.  You need to pick a time and date that works very well for you.  Every person has a time of the day where they are at their peak.  For some it is the early morning, most likely with the aid of their coffee, but for others it is right after lunch.  Think about what this time is for you and make that time your GMAT test time.

Location, Location, Location.

Pick a location that you are familiar with or become familiar with the location that is offered.  If need be take a drive to the facility and figure out how to get there and where you will be parking, because you do not want to have the stress of finding parking tax your brain on that day.

It’s a date?

You need to pick a date that will not be surrounded by chaos.  This might seem obvious, but don’t pick a date when your parents are coming to visit or you have a vacation starting the next day.  You will be distracted and that can hurt you.

Treat the day as a vacation day itself.  If possible tell your boss that you need to take the entire day off, or if you are taking it in the morning, maybe a half day the day before and a half day for the test.

If you have time in the morning do something mildly athletic, take a jog or go for a walk to get the blood going.  Do not roll out of bed, slam a cup of coffee and wing this thing (although I am sure some of you believe that is when you are at your best).  Eat something, but don’t stuff yourself, you don’t need the blood digesting when it needs to be working on Data Sufficiency.

What are you wearing?

Depending on the time of year and given the fact that you do not know what the facility will be like, I would dress with some layers.  Walking into a test center with so much A/C blasting that it makes Siberia feel like the tropics without a sweater or sweatshirt would be really bothersome.

Finally, have a good attitude about it.  You can take it over, but set your goal high and aim at it.  If you aim at 500 then 450 becomes a real possibility, if you aim at 800 then 750 becomes more real.  Don’t sell yourself short, it’s a game and if you prepared you have a shot at doing very well on it.

Good luck.