A practice of alternate nostril breathing and 'Super Brain Yoga Squats' are well known to harmonize and balance both sides of your brain for peak performance. Check out www.superbrainyoga.org. There is also a nice youtube video about super brain yoga. I hope this helps and good luck on your test.

For any test I think the main component is adequate preparation. If you have studied the appropriate material, to the best of your ability, then doing some exercises ( like Brian suggested above) will help synchronize the brain and will be beneficial to your overall mindset. I also believe that old adage - a good night's sleep beforehand will add to your alertness during the test.

The best thing I have found to do prior to a test (on the day itself) - or indeed any pressure event like a job interview, public performance, presentation etc. - is to get yourself into The Vortex as Abraham calls it.

It's a kind of flow state where you are in close alignment with your broader self and, when combined with the mental focus required for the event, causes you to become extremely receptive to intuitive impulses. You end up doing, saying or acting in the perfect way to achieve the end result you are after.

As someone who can't resist getting himself into pressure situations (there's just something about the thrill of extreme focus!), I've been testing out this approach over the past several months and I can personally vouch that getting into the Vortex first works tremendously well compared to any other non-spiritual or action-oriented methods I have tried.

You can, in effect, just relax during the event itself because you are in such a mental state that if you are required to do something it will be received as an overwhelming impulse that you can just easily go with. It can just feel as though you are a spectator to what you are doing...it's like you are almost on auto-pilot. You'll know exactly what I mean if you've ever experienced a state like that before.

I guess, in short, I'm just saying to get yourself happy somehow before the event and then go with your intuitive impulses during the event.

It's an application of Joy first. And anything else you have time for.