From my experience,
I had been using the ncert books for the first reading and then tried solving questions from standard books but unfortunately I - this is very subjective - just couldn't get through them. There were factual based questions that weren't present in ncert and had to refer to another material for the same sub topic and repeatedly fail to get a clearer concept.
Basically, you will have to read - comprehend - memorise - and analyse the topic the perfection in which is highly dependen on failure!
So sorry bro - there is no shortcut in this marathon for my side.