Well, I'm surprised and gratified by the response. I apologize for not thanking folks for comments and favourites. But there have been literally hundreds of responses. I gave up counting them.
I'm trying to keep up with all the comments, at least. Someone asked if I would do a tutorial. I don't know how to tell you how to do what I do. I just picked it up by trial and error over the years. The single best thing I can tell you to do is get a copy of "Dynamic Anatomy" by Burne Hogarth. Hogarth drew the 'Tarzan' newspaper strip for many years, did a lot of advertising illustration, and founded the school where Eric Stanton learned his craft. (Gene Bilbrew as well, but, well, whatever.) Hogarth did a whole series of books on drawing hands, heads, and clothing, but his 'Dynamic Anatomy' is the definitive book of the series.
I've also been thumbing through the 'Digital Painting Techniques' series, which you can find on Amazon.