Aspirants can measure their progress during UPSC exam preparation through several effective methods. Regularly practicing with mock tests helps simulate exam conditions and assess strengths and weaknesses. Maintaining a study journal to track topics covered and mastery levels is beneficial for self-reflection. Participating in group discussions can also provide feedback and alternative insights. Time management strategies, like creating a study timetable, allow candidates to evaluate their adherence to schedules. Lastly, setting milestones for various segments of the syllabus can provide a structured framework to measure progress systematically.