From years of taking standardized nursing tests (NCLEX PN and NCLEX RN, CEN, ONC, RN-BC med-surg) here are my tips...
You're smart and you passed nursing school. You know this stuff. Don't walk into the test already giving yourself a failing grade
Go with your first answer... It's usually correct
Relax, you won't know everything on the test... it's just how it goes. DO NOT GET FRUSTRATED BECAUSE YOU DON'T KNOW AN ANSWER, MOVE ON! Taking a SWAG (Scientific Wild A**ed Guess) is perfectly acceptable every once in a while
READ THE QUESTIONS CAREFULLY!!!!!
Don't read into the questions. The information that is presented is all you need to know. Don't make it more complicated than it needs to be.
When in doubt ABC's... If that doesn't apply, life/limb/eyesight... If that doesn't apply, what would you want done if you were a patient?
What areas did you do poorly on in school? Study those.
Sleep well the night before. Consider taking the night off! Cramming for the test until 2am of the day you test won't help and will likely hurt as you might be less alert.
Take the test when you're most awake (ie if you're a morning person take the test in the morning).