One of the most important tip I can give you is Don't answer any question which you are not hundred percent sure about. It is because even a difference of 1 mark can make your rank jump by 1000s. So if you give a wrong answer, you get negative point and that effect your rank.

Second at least do the last 10 years paper as a few questions do get repeated. And just try to stay focused and don't lose hope. I hope I could help