Hello Allan and thanks for your reply!
Your idea is an interesting one and I will try it at my next OS session. I do struggle with the proper placement of the eyes - both placement of distance and the plane of the eyes. I am generally drawing out an outline first with basic shading of planes rather than finishing. None the less, I have to work more at proper placement of features and your suggestion is a good one to try.
What I am working out -should be- pretty basic stuff to most portrait artists, but I suspect it is not for many and I thank you all for putting up with my posting of less than stellar drawings on this fine forum.
This is the point. As I say in my signature, drawing is the foundation of all we do as artists. Many of us need work in this area and I am sort of a poster child for the maladies that affect artists today.
I am hoping others will step up and take on this challenge too.