Effective communication strategies for candidates in the UPSC interview include practicing active listening, maintaining clarity in responses, and articulating ideas confidently. It is important to structure answers logically, using frameworks where applicable, and to be aware of body language. Candidates should also keep their responses concise and relevant, demonstrating organized thoughts. Additionally, showing a rationale behind answers and relating them to real-world examples reflects deeper understanding. Regular mock interviews can further enhance these skills, building both confidence and communication proficiency.