Aspirants can prepare for debates on contentious issues relevant to the UPSC exams by conducting thorough research to gather diverse perspectives. They should analyze both sides of an issue, focusing on credible sources and current data. Engaging in mock debates can help build confidence and improve argumentation skills. Understanding the socio-economic and political implications of these issues is crucial for developing a well-rounded stance. Practicing public speaking boosts articulate expression, preparing candidates for effective participation in interviews as well.