In the first painting turpentine should be used as a medium

In the first painting turpentine should be used as a medium, for it leaves the pigment good in texture and dull of surface—an excellent condition for receiving the second and ultimate paintings, when oil is employed.

Commence by rubbing in the background in its proper value and color. This done, the head may be attacked with a full brush, and with as close a reproduction of the effect it presents to your vision, both in general light and shade, as you are capable of making it. Do not look at first for the highest lights nor for the deepest darks. Half close the eyes, and endeavor to resolve this object to the simplest and most direct impression. Mark the tone of the hair in relation to the face and to the tone behind it. Everything should be reduced to the fact of a background with an object, a spot, of a certain form and color, in front of it. The contour and proportions will announce that it is a head; the subsequent paintings and the definition of the features will tell that it is an individual.