For example in paper 1 & 2, practice more problems by solving it. Few Suggessions:
1. Understand the concept.
2. Understand the problem given
3. Solve it by looking into the answer
4. For the next time when you see the problem, try to solve without looking into the solution
5. Mark * in the question which you were unable to solve in the first attempt and proceed to the next problem
6. Go ahead with other problems
7. During first revision session, take the problems which you have marked * and try to solve the same
8. If you were again not able to solve it correctly, then mark one more * and continue with 6 above
9. Continue to mark * during 2nd 3rd and further revisions
10. During exam period, try only those questions which has more * (Which were more difficult)
You can easily crack those questions in exam.
You may have such other techniques for theory papers.