Hello Siddanth!

Glad that you have thought about Cengage.  It is the best series for JEE preparation in my view. Most of the people don't know about this. Cengage is very good for problem solving. 

• First of all,  go through the concepts given.  Everything is given elaborately though some of the sub-topics are out of syllabus.
• If you already know the concepts, don't waste time by reading theory only.
• Make sure that you refer all the solved problems by solving them without looking at the solution and then clearly check the solution if if your amswer is right so that you may not miss any concepts.
• I think,  time gets over by this only. During the time of weekly exam, you can solve the unsolved problems with different patterns.
• For maths,  multi correct and paragraph problems are really good.
• For physics, subjective problems are good and give you the solutions and ideas to solve.

Hope this will help you!

Thanks :)