1. Don't forget the basics. Civil service exam is as easy as final exams in highschool. Review grammar and correct usage. In Mathematics, don't forget fractions and decimals. English and Mathematics are the utmost priority in reviewing since there are lots of them in the exam.

2. Be fast answering the questions. I know you are a genius but you if you are slow, you will surely fail the exam. Skip first the hard questions especially in Math, you know you can answer the question and even it is taking you too long to solve the problem, you don't want to skip it because of your PRIDE. 

3. Sleep early the night before the exam. Just relax and have confidence. Eat your breakfast. You can bring water with you. Also, bring a watch so you can track your time when the battle begins. 

4. PRAY ! Seriously. Pray :)