Preparing for optional subjects in the UPSC mains requires nuanced strategies, including a deep understanding of the syllabus and selection of topics based on one's strength and interests. Candidates should read extensively from various reliable sources and focus on conceptual clarity. Regular practice of answer-writing ensures familiarity with the exam format and marks distribution. Engaging with previous years' question papers helps in identifying important themes and patterns. A consistent revision strategy, along with integrating current issues related to the optional subjects, enhances the depth of responses, yielding better performance.