The only difference I can discern is that when my left shoulder dips below my chin (as supposed to more above my chin), seems to be a cleaner hit.
My normal bad shot is a hook.
By shank, I presume you mean that when you hit the ball it veers low and strong to the right.
If so, sometimes I'll do this a couple of times when hitting bucket...for me it's most always that I'm hitting the ball with the hosel of the club.
That tells me I'm standing too close, so I drop back a little away from the ball at setup and I typically stop doing this.
Hope that helps.