test day warm up..

Don't do anything on the test day - just go over strategies and some checklists that you may have.

My preferred time to take the test would be morning actually since you would not be yet tired and still fairly fresh, but it is not a big deal.
I very much agree about not running a marathon the day before, but I think you should take a test 24 hours before the actual test to get a feel for the stamina and effort you will need to put in - many people underestimate and by the time they reach the verbal section, they are "out of breath"

I have a number of suggestions for the week before the test:

1. Get some rest the week before the test. If you have a job, take a break at least for 2-3 days before the test day. Do not do much on the day before the test. You need to accumulate your strength and then shoot it out on the test day; just like the professional athletes do when they train. The idea is to work out a lot before the competition and then rest for a few days, thus having getting your body used to regular work out, and then take a break for a day, therefore, having the double strength on the D-day.

2. Take a few full GMAT’s in the last week so that you know how it feels to sit for 4.5 hours and take the full test. By doing this, you will know how much effort to put into the essays and each section because you don’t want to be worn out by the verbal. Also, try to take the practice tests at the time your real test will be, e.g. 10 am, 1 pm, etc. Some people say that it helps to do some questions in the morning before you go the gmat, but I think essays do a good enough job warming up the brain. Also, during the last few weeks concentrate on polishing your strategies and timing, rather than math or grammar.

3. It is important to know where the test center is and how it feels inside, etc. Especially useful is when they start letting people in. For example, when I was taking my GMAT in Moscow, the appointment said 10 am, but I needed to show up at least an hour in advance, so I did come at 9 and met about 10 other people with whom I would be waiting for another half an hour till 9:30 when we were permitted to start the registration. It is not lethal to wait for half an hour, but if you are waiting to take GMAT that you were preparing to for half a year and that determines your future, you will remember those 30 minutes of waiting.

4. When you come, you are supposed to have an ID and whatever else you want, but the administrator won’t let you have anything except the ID, 5 pencils, 2 ear plugs, key to your locker, and the scratch paper booklet with you (I also had computer glasses). The rest will be put away into a locker, about 15”w x 20”h x 15”d. They will give you some markers but with that collection of things: markers, booklet, glasses, key to the locker, ID, and ear plugs, it will be pretty bulky to get seated. Before the GMAT, you will be picking out the schools you want your score tests sent to (5 is max); you don’t need to know the codes in advance; there will be names of schools in the alphabetical order. Actually, it is good that you will busy picking schools, it will relieve the stress; you have as much time as you want. After that, the two essays will torture your mind for an hour.

5. A good idea is to change the setting in the last few days before the test. I had a great chance to go to another city and take my test there (since the center in my town was full). I arrived on Friday and on Saturday took TOEFL (I am an international student). As the result, on Tuesday, as I came in to take GMAT, I already knew the test center location, the policies, the fact that the 5-minute breaks can be as long as 50 minutes, etc. Also, I knew that I have to fill out a disclaimer before I could take the test, so I immediately headed for the table with sheets. Since I have gone through the procedure just two days ago and TOEFL was very easy and I got the max points, I was fairly relaxed while getting seated at the computer and positioning my pencils as well as sticking the ear plugs. (it is important that you know how to use them). In addition to all those benefits, I was in Moscow and was separated from all of my friends/work/problems and could concentrate on the upcoming test and relax. It is also important that there are no troubles sitting in your head during the last days before the test. Don’t build up psychological pressure; try to think about pleasant things.

6. Psychological pressure and worrying is destructive. If you concentrate on your overall standing wile taking the test, you will not do your best. I had no idea how good I was doing. I just did not know. I was constantly doubting my answers on the verbal (I was never sure about the CR). Math was easier cause I did check my answers and was sure I got the questions right, yet still I scored only 49 out of 60. Do not worry about the test, you will have worried enough by the test day. See nothing but the question you are working on and the time you still have to complete the section.

Physical things
7. Know how to use the ear plugs; conveniently enough, you will find a set of headphones near you (left there by the toefl kids), and you can use them too. When I was taking my GMAT there was a good number of distractions: keyboard typing, computer fans, electric lights buzzing, mouse clicks, passing cars that I could see in a crack in the blinds, door opening and closing and people coming in and out. It is important not hear all of that and be in the questions. When I was taking my GMAT, I had a very nice looking sample of a female sitting right next to, but unfortunately, after several looks, I figured she did not come to the ETS center to meet the man of her dreams but to take the test, so I followed her example. I wonder what she got… I tried to look into her unofficial score report, but she folded it fast enough for me not to see the score. I was not too hasty to hide my 750 though, but it was not my day.

8. When I came originally it was cold in the room because of the air conditioning and I thought that I dressed too lightly and that I will not be able to concentrate on the test due to the temperature, but very soon it got pretty warm and even hot (the room was small, so it even smelled with people). Some say that it is the best when you are a little cold – they say the brain works better…. I think it is true. Use your regular cloths, something that is comfortable and can be conveniently taken off if needed. As the official bulletin says, dress in layers.

9. Do not wear out yourself before the test. The test will wear you out should that be the goal.


Break
10. A good thing to do during the break is to go to the bathroom, even if you need not. You will get some rest, won’t be staring at the computer screen, and will get occupied with some simple thoughts such as jamming zipper or a stain on your shirt. One trick that helps is getting some cold water on your face and esp. temples. This is known as a diver’s reflex. God or the Mother Nature (whoever you believe it was) has taken some precaution to save us in case we, humans, drop in the water. As the result, when your face hits the water, the brain gives an alert to the body and slows down metabolism and other body functions. Thus freeing up to more oxygen for the brain to use up, thus allowing us to stay under water longer. Of course this is no way of getting a high score on the GMAT, but it will help to flush the brain a bit, a little reset button if you wish.

11. Get some food, a sugary drink, and some water with you to the testing center. It is better to have more. You never know how you will be feeling, so try to be prepared to anything; often when nervous, the stomach gets a mind of its own. Good nutrition for several days before the test is also good; it lets you be physically well and enhances endurance.