What suggestions can you make for prepping to take the GMAT exam?

Alison's Contribution: I can suggest the following which was pretty much what I did 10 years after graduating:

First: Understand how your answers will be scored.
1. Brush up on the maths equations and facts set, how to answer types of information - there are some good on-line resources.
2. Buy one of the practice test books and sit through them in the way you would sit the exam - even so far as filling in answers on a separate answer sheet.
3. I can't remember the acronym, but look up the technique for answering questions to get the highest possible score. I believe it has the following steps:
a) Answer the ones you can do quickly.
b) Guess - eg eliminate two choices and then take the best guess for the two remaining if you can't work it out.
c) Work through the ones you have found difficult.
d) With any remaining time, check through your answers.
4. Arrive with plenty of time, something to drink and a snack to keep the energy flowing. Have extra pencils, erasers, etc. and everything else you need.

Panic: If you panic, close your eyes and take a deep breath, hold for 10 seconds and then let it out (or any other breathing mantra) to focus your energy. (Practice these techniques so that you can utilise them in the test situation.)

According to something I read, your scores will be decreased if you don't answer all the questions, so it's important that you learn how to make an educated guess in the time available.

Afterwards: As always, know that you did your best on the day, no one can ask more from you, so don't beat yourself up afterwards. Just congratulate yourself on doing the best job you could.