Mechanics

[schmitty1973]

I've recently just learned (Thanks to this board) that you don't throw a flag for pass interference until the play is over. So what other proper mechanics are gone over in the clinics that aren't covered in the books? I won't have an opportunity to attend a clinic until next year, so I would like to get some insight for this season.
Also, I was once told that I shouldn't back-pedal. Is that true also?
I always see it done by the NFL and college, so I can't figure out why it wouldn't be correct.