Thanks Janel! (you flatter me though. . .

)
Mischa, thanks! I used to use an underpainting technique. . . but found for me that this wound up in a lot of rework/redrawing as I'd inevitably lose the likeness and have to 'recapture' it when laying in with color over the underpainting. So now will start directly with a very thin layer of color (a wash in this case but more usually color applied and scraped back with a palette knife) just to kill the white of the canvas, rough in position, and cut the 'drag' on the brush of getting the first layer of paint on. If you're interested there's a WIP of this
here.
Tom and Marina-- thanks so much!