Eat a decent breakfast (something with a good amount of carbs and protein - I had a PBJ sandwich) and bring a small, quick, easy to eat snack - dried fruit or a granola bar is good. You don't want to feel weak or have a headache because you are hungry.
Don't stay up all night Friday trying to cram - review some notes or look over your weakest area, but then relax and get a good night's sleep.
Ask for a left-handed desk if needed.
Skip the most difficult looking, longest math and chem questions, unless you've practiced under timed conditions and are sure you can finish these sections in time. When they give a five minute warning, go back to any questions you've skipped and quickly select an answer that at least makes sense - you should be able to estimate in the quant. section and at least cross out one or two choices for some of the questions. Don't leave anything blank! If you only have a minute left just bubble in like mad - answering 10 questions randomly should do you much more good than carefully figuring out that one last question you were stuck on.
When it's over, don't dwell - it's going to take 5 weeks to get results, and you can't be sure if you aced it or bombed it until then. If you aren't applying to pharmacy school until next year, it might not be bad to quickly jot down the areas that you felt weakest in (ecology? nomenclature? be as specific as you can) so that you can remember what's on the damn test months from now. Don't share that list - it's not ethical - but keep it to yourself because they do repeat questions/have similar questions from test to test. I'm sure that this is not violating the "don't discuss specific test questions" rule since you are just making notes for yourself.