Yes your Concept must be clear.
Solve problems as much as you can.
If you r in PE II,solve past problems of final.
keep in mind all formulae and formats.
try to solve different problems.
Best of Luck
study ICWAI suggested answer and solve ICWA past term question. solve probem of Saxena and Vash*t/ P v Rathnam. clear concept from- Cost Accounting- By B K Bhar
Cost Accounting- Bhabotosh Banerjee