Aspirants can develop their public speaking skills for effective presentations during UPSC interviews by participating in workshops or engaging in practice sessions. Joining groups like Toastmasters provides a structured environment to enhance speaking abilities and receive constructive feedback. Regularly practicing speeches on various topics allows for confidence-building and mastery of articulation. Furthermore, demonstrating knowledge about current affairs during practice interviews helps to refine their responses while addressing potential questions, preparing candidates to convey their ideas effectively.