GS3 has been my favourite and I generally reserved it to study when I was bored of the remaining topics. It has many sub-parts, so I made topic wise notes and kept adding points from current affairs over time. Subject Sources My notes Economy Mrunal videos (great to start with) NCERTs Any standard book (I did Ramesh Singh, totally optional) Current Affairs Economic Survey (I looked forward to this document all year. It was my favourite read and I went overboard by making notes myself and reading past 5 years surveys. You may refer to my notes for value add points to use in mains) Budget Mrunal notes GS3 mains notes Economic Survey and Budget notes Agriculture notes Security Any standard book (I did Vajiram yellow book) Current affairs Security notes Environment Shankar IAS material Current Affairs ARC for Disaster Management (find any summary) Env and DM notes S&T Current affairs I practiced diagrams and graphs...