Before taking a test such as the SAT there are many things you should do to prepare. When you are prepared for a test it makes you feel good, and your confidence is boasted, which in turn usually results in a higher score. You will need to study your material (any notes, text or assignments you think might help you) but don't cram or chances are you will just get information jumbled up in your head. To take a test and succeed, as Mark Twain once said, " the secret of getting ahead is getting started. The secret to getting started is breaking your complex overwhelming tasks into small manageable tasks, and then starting on the first one." This is very true, you need to break down your time and study little things at a time, such as maybe your weak in Geometry, so concentrate on studying that for a while. .
When taking a test successfully you need to overcome any anxiety you may have. It has been found that people that relax, get a good nights sleep, and eat something before you take the test, usually do better. You need to prepare mentally as well as intellectually. Make sure you read the directions thoroughly and budget your test taking time carefully. A really effective way of preparing for a test is to make flash cards or mapping diagrams, this has been known to incredibly help boast scores. You should also take practice tests and keep taking them until you feel comfortable with them. The more familiar you are with the test format the more relaxed you"ll be, and the more relaxed you are the better you"ll do. Personally I recommend buying an SAT (or whatever teat your taking) book and going through it that way you can see what your weaknesses are and make them stronger. If you"re a person that chokes on test you should really take a class on becoming more familiar with it.
When you go back to check your answers don't second-guess yourself unless your 100% positive you put the wrong answer, first instincts are usually right.