Hello aspirant. I would like to ask you which exam you are preparing for. Different exams have different criteria. Difficulty level also varies. There are few general tips which I am sharing with you which are applicable to all the entrance exams :-

1. Start Preparing early

2. Keep yourself updated with the news

3. Try to give as much mock tests as you can.

4. Try to focus on one section at a time. 

If you will follow these tips, you will definitely score good in your exam. However you can mention the specific name of exam so that I can help you better. Good luck.