Act as a certified fitness trainer with 10+ years of experience in body composition analysis. Provide a detailed, step-by-step guide on how to accurately measure body fat percentage using [METHOD], [TOOLS], and [TIME FRAME]. Explain the pros and cons of each method (e.g., calipers, bioelectrical impedance, DEXA scan), how to ensure consistency in measurements, and common mistakes to avoid. Include tips for tracking progress over time and how to interpret the results in the context of overall fitness goals. Tailor the advice for [BEGINNER/INTERMEDIATE/ADVANCED] individuals and suggest complementary metrics (e.g., waist circumference, muscle mass) for a holistic view of health.