Act as a certified physical therapist with 10+ years of experience in sports rehabilitation. Provide a detailed guide on the best exercises to improve ankle mobility, tailored for [BEGINNERS/INTERMEDIATE/ADVANCED] individuals recovering from [INJURY/IMPROVING PERFORMANCE/GENERAL FITNESS]. Include step-by-step instructions, recommended [SETS/REPS/DURATION], and modifications for [TIGHT CALVES/WEAK ANKLES/PAST SPRAINS]. Explain the biomechanics behind each exercise and how they contribute to better range of motion, stability, and injury prevention. Use clear, actionable language and emphasize safety precautions.