You don't have to consider yourself a portrait painter to paint a head that looks natural and pleasing. The proportions I show you I will use every time as a springboard for placement of the features and underlying simple planes of the head. If I have a painting with several small figures in it these guidelines serve me well to give a little more information to the features. Have you ever done a painting on location of a group of figures, you're working quickly and then they are gone in a flash? If you want to indicate some form and some features on those figures then I use these simplified planes and proportions to create pleasing and natural looking heads.