A successful answer in the UPSC Mains exam should have clear and concise structure, addressing all components of the question. It should start with a relevant introduction, followed by a well-organized body that presents logical arguments and evidence. Utilizing bullet points for clarity and flow can enhance readability. Each answer should include examples, case studies, or references to relevant studies to demonstrate understanding. A strong conclusion should summarize key points and provide a solution or perspective. Crafting well-structured, analytical answers will significantly contribute to scoring well in the exam.