Start at article 110 and READ the NEC every night leading up to the test for 1/2 hour. When the NEC says "per section ...." go read that section. When a definition or term is unfamiliar, go look it up in the NEC. This will naturally train you to "look it up" as you will need to for your test.
Do not read more than 1/2 an hour a day. Do not study or read the night before the test. Do not focus on calculations, they are only a small portion of the overall test.
When testing, READ the question, ANSWER the question, IGNORE additional and unnecessary information.
No heavy meals the night before or the morning of, no drinking the night before or while studying, get a full nights sleep!
Good luck!