If you begin with the middle-tone and work up from it toward the darks so that you deal last with your highest lights and darkest darks, you avoid false accents. See image John Singer Sargent
Color is an inborn gift, but appreciation of value is merely training of the eye, which everyone ought to be able to acquire. See image John Singer Sargent
A portrait is a picture in which there is just a tiny little something not quite right about the mouth. See image John Singer Sargent