To write compelling essays in UPSC, candidates should focus on several strategies. They should start with a strong thesis statement and maintain a clear structure with an introduction, body, and conclusion. Using real-life examples and case studies to support arguments adds depth. Maintaining coherence and a logical flow is essential, as well as adhering to a relevant word count. Practice through regular writing and receiving constructive feedback also play vital roles in developing impactful essays that stand out in the Mains examination.