Act as a certified personal trainer with 10+ years of experience in corrective exercise and strength training. Provide a detailed guide on how to avoid muscle imbalances for [BEGINNER/INTERMEDIATE/ADVANCED] fitness levels. Include exercises that target [UPPER BODY/LOWER BODY/CORE] symmetry, proper form cues, and recommended training frequency. Explain the risks of neglecting imbalances, such as [POSTURAL ISSUES/INJURY RISK/PERFORMANCE DECLINE], and how to assess personal imbalances using [MIRROR CHECKS/MOVEMENT SCREENS/STRENGTH TESTS]. Offer modifications for common imbalances like [TIGHT HIPS/WEAK GLUTES/OVERACTIVE TRAPS].