Strategy I followed for GS-3 paper-
Indian Economy and related topics, Inclusive growth and Issues, Government budgeting- Made basic understanding from Mrunal Sir's notes, supplemented the dynamic knowledge with Newspapers, Mains 365 notes, Yojana, Economic Survey and Budget( covered by Mrunal Sir)
Cropping pattern and related topics along with subsidies,PDS, etc- Vision's value added material( will upload on the channel itself)- Mrunal Sir's notes, Mains 365, Geography NCERTs, Selective topics under Yojana and Kurukshetra.
Food processing and related topics- Vision IAS value added material ( will upload on channel) along with Mains 365, Mrunal Sir's notes.
Land reforms- Sociology NCERT class 12th, Current affairs.
Effects of liberalisation on Indian Economy, Infra, Investment models- Mrunal Sir's notes, Mains 365, NITI Aayog's document, Various committee reports( Rakesh Mohan committee, etc)
Science and Technology-
Basic understanding can built through referring the NCERTs, Current affairs through Mains 365, IE articles.
Environment related topics- PMF IAS material, Geography NCERTs, Mains 365, IE articles.
Disaster and Disaster management - NCERT for disaster management, Mains 365, Geography NCERTs, IE.
Internal Security- Build basic concepts through Ashok Kumar Sir's book, then Referred to Vision IAS material, Mains 365, IE.
Paper-3 is more about putting in greater arguments along with appropriate usage of data, Case studies, reports recommendations and innovative models to provide dynamicity to the content.
Along with this, I found mapping, Flowcharts, diagrams, timeline charts come to my rescue in case I found the shortage of space and Time.
Additionally, I used the mention of schemes, initiatives already taken and in conclusion, I usually wrote Way forward so as to provide holistic look to the answer.
And lastly, going through PYQs and related themes provides the apt direction to this dynamic paper.