To prepare for descriptive type questions in the UPSC Mains, candidates should focus on clarity and coherence in their writing. Developing a structured approach is vital, including an engaging introduction, well-developed body paragraphs, and a concise conclusion. Regular practice through timed essays can help improve writing speed and thought organization. Candidates should also familiarize themselves with previous year questions to understand common themes and topics. Using bullet points for data and examples can enhance readability. Lastly, seeking feedback from mentors or peers on drafts can provide valuable insights for improvement.