This film is from 2003 Norm Chow era USC TV cut-ups, which is all I had to study before access to coaches film became more prevalent. These are the best examples of the right and wrong way to run the Slant route that I have ever seen. Both examples are from the same game and both were 3rd Down plays. I coach my WRs running the Slant route to attack the inside # of the defender with their three steps. I have heard coaches before tell their WRs to attack the outside # to open the DB's hips and then come inside. That works in theory, but as you will see in the cut-ups, it does not always work in practice. Mike Williams was a Freshman running the Slant route in the first cut-up. He doesn't attack the inside # of the defender to gain leverage (position) and he ends up running into the CB. It's a sloppy route by an inexperienced player that lead to a Punt on that possession.
The second cut-up shows a veteran WR, Kerry Colbert (I believe), running the Slant the correct way: attack the inside # to get leverage, stay low and stick the foot in the ground with a head nod away, and catch the ball with the hands away from the body. It's a thing of beauty to see proper technique ruthlessly destroy opponents time and time again.
Versus Press coverage, I do coach my WRs to use a Diamond release where they work outside and then back in, but that's vs. Press, not vs. Loose Man or Zone coverage. That will a future mini-post.
Here's the film: