Best practices for writing answers in the UPSC Mains Examination include clarity, structure, and relevance. Candidates should ensure that their answers directly address the question, adhering to the word limit. Starting with a concise introduction, followed by well-organized main points, and concluding with a summary enhances readability. Using bullet points or headings can help in clarity and presentation. Incorporating relevant examples and facts can strengthen arguments. Additionally, candidates should practice writing regularly to improve speed and coherence, as well-organized responses score better in evaluations.