Hello, here are some of the tips i suggest

1. Practice more the standard problems.

2. After practicing standard problems then you refer previous years papers then iam sure that you can answer 70% of the problems.

3. Most of the students fail in answering short answers so you just read some definitions and basic problems, because most of the short answers come from basic problems and definitions.

4. Finally by learning basics well you can also answer long answers perfectly this helps you in scoring 90% of marks. The rest of marks you can earn by practicing more and more problems.