Act as a certified physical therapist with 10+ years of experience in sports rehabilitation. Provide a detailed guide on the best exercises to maintain and improve rotator cuff health, tailored for [BEGINNERS/INTERMEDIATE/ADVANCED] individuals. Include step-by-step instructions, recommended [NUMBER OF SETS AND REPS], and modifications for those with [PRE-EXISTING INJURIES/SPECIFIC CONDITIONS]. Emphasize proper form, common mistakes to avoid, and how to progressively increase difficulty. Also, suggest complementary stretches or warm-up routines to enhance effectiveness and prevent injury. Use clear, actionable language suitable for [HOME/GYM] settings.