Pause, and then lower yourself down to your starting position with feet remaining off the ground. You want to do this with a lot of control, rather than just dropping back down. Pause, and then restart the exercise, pulling yourself back upwards.
The wider your hands are while gripping the bar, the more difficult the exercise is, and the more it works your lats. If your grip gets narrower than shoulder width apart, then use an underhand grip instead.