Both lifters try to pull too far and too high on vertical pulling motions such as pull-ups and lat pulldowns. Rather than trying to touch the bar to your chest or reaching your chin over the bar (both of which can produce dysfunctional mechanics), the goal should be to achieve proper upper back and lat activation.
Originally coined "The Bear" by John Davies, this series of five exercises in one teaches the body to move with great ROM in a fluid, powerful, and fast manner. It's fantastic as a total body warm-up, improving overall power production and motor skill coordination in a short period of time.