To segregate main ideas in UPSC studies, candidates can adopt strategies like mind mapping, using charts, and summarization techniques. Breaking down complex topics into sub-topics allows for easier retention. Utilizing bullet points for key facts and figures is also effective in highlighting main ideas. Moreover, conducting regular self-tests and discussions with peers can reinforce clarity. Developing a habit of linking related concepts helps in establishing connections and understanding overarching themes, facilitating a more organized and efficient study process.