Most Important thing is the CONCEPT. You must show that you have clear understanding about the question asked & its answer.
Other relevant points are :
1) Quote relevant sections of the Act;
2) Quote amendments, if any;
3) Quote relevant e-form numbers;
4) Quote relevant case laws;
5) Always answer point-wise, dont write bulk paras;
6) Try quote few recent case laws;
7) Try to attempt all questions;
8) Read the uestion carefully;
9) Understand the question carefully before you start answering;
10) Use clear handwriting.