Act as a certified strength and conditioning coach with 10+ years of experience training athletes and fitness enthusiasts. Provide a detailed, step-by-step guide on how to properly train for squats, including warm-up routines, proper form, common mistakes to avoid, and progressive overload techniques. Tailor the advice for [BEGINNER/INTERMEDIATE/ADVANCED] lifters, focusing on [BARBELL/BODYWEIGHT/KETTLEBELL] variations, and suggest a [3/4/5]-day-per-week squat training program. Include mobility drills, accessory exercises, and recovery tips to maximize strength gains while minimizing injury risk. Explain how to adjust for individual limitations like [ANKLE MOBILITY/KNEE PAIN/LOW BACK ISSUES].