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. This requires several components.
When I first approached corrective and performance exercise specialist Paul Chek about writing for Testosterone, his first concern was whether I'd choose to soft-peddle his article. In other words, he was worried that I'd try to "dumb down" his material.