Strategies for writing effective answers in the UPSC Mains exam include using a structured approach like introduction, body, and conclusion. Begin with a concise introduction stating your understanding of the question. In the body, address the core points with clear reasoning and examples, ensuring relevance and depth. Use bullet points or subheadings where applicable to enhance readability. Finally, conclude by summarizing your arguments or offering solutions. Regular practice of previous years’ papers can help in developing this skill, along with time management during the exam.