So, what led to the muddy guitar tone? An enquiry, part I

Our dear friend JT Spangler wrote me a couple of days ago, apropos of the recent “muddy guitar” series of posts, with this question:

It might be beyond the scope of your list, but I'd actually love to read your suggestions for working producer-to-artist to overcome the bad idea that led to the bad guitar tone in this initial post in the series. I think t…