In the last 3 years, a lot of things have changed about UPSC-CSE preparation. Core books like NCERTs, Laxmikanth are a great starting point but they need to be substituted with your own notes that are precise and help you recall everything.

Every Topper has put in an extraordinary effort to streamline their notes. It was an obsession. It took them multiple iterations and failed attempts to finally get to a version that helped them cut down on the revision time and remove the dependency on the core books. 

Take the example of Council Acts that you start with. You need to understand

1. How the executive/legislature has been evolving with each act, and their powers. 
2. The new bodies being created BOC, COD, and their mandates.   
3. How were the Provinces being impacted?
4. Finally, the key features and points to note for each Act.  

Likewise for various other topics in Modern History.