Sit down on a lat pulldown machine with a v-bar attached to the top pulley. Adjust the lap bar so that your body is held firmly in place throughout the entire exercise.
Grip the bar with your palms facing in and start the exercise with your arms extended above you so that you feel a good stretch in your lats.
Lean back slightly, position your shoulders down and back, retract your shoulders blades slightly, puff out your chest and keep a small arch in your lower back.
Pull the v-bar down until it touches your upper chest and you feel a strong contraction in your lats, and then raise the bar back up until your arms are extended before repeating.