Set the assisted pull-up machine to the appropriate support level. Stand or kneel on the platform. Grip the handles with an overhand grip, slightly wider than shoulder-width. Engage your core and keep your body straight. Pull yourself up, driving elbows down and back until your chin clears the bar. Pause at the top, contracting your back muscles. Slowly lower with control. Repeat.
Maintain a firm, relaxed grip. Focus on back muscle engagement, not arm pulling. Control the movement throughout. Avoid swinging. Gradually reduce assistance weight as strength increases. Keep shoulders down and away from your ears. Exhale on the pull, inhale on the descent.