Start preparation early. You should work to build a lead over others taking the exam.If you want above-average results, work ahead of the curve.
Revise actively by attempting questions/writing essays etc. Don’t just sit with a book.
Seek out someone who has gone through the process successfully and utilise his/her knowledge.
If you know that you are the type to struggle with pressure on the day of the exam, try writing down the things that make you anxious about 20 minutes before the exam.
Simulate test conditions and take mock exams (if they are available). Then go through questions and develop your understanding of areas you found difficult.