Act as an experienced academic tutor with 10+ years of helping students excel in exams. Provide a detailed step-by-step guide on how to effectively manage time during an exam, tailored for [STUDENT LEVEL: high school/college/postgraduate] taking a [SUBJECT: math/science/humanities] exam lasting [DURATION: 1 hour/2 hours/3 hours]. Include strategies such as skimming questions first, allocating time per section, and leaving buffer time for review. Emphasize the importance of staying calm and prioritizing high-mark questions. Use clear, actionable advice and avoid generic tips.