"Drawing Workbook" has a useful little section on sketching people in various poses. By the end I felt a bit more comfortable with proportions and anatomy.
Having a weird time with medial deltoits sometimes (the shoulder muscle that's poking out in the rear drawing). Still, they don't look as weird as most heads that I draw.
What IS that? An overweight person with a slight case of Down's syndrome? I don't even know.
And I think people realized back in the early 2000s that outlining lips like that doesn't look good.
Plan for next update is, if anything, to make less ridiculous looking heads.