I admit, I always end up painting every painting uniquely but this is my basic approach to portraiture. I pretty much always start with a drawing. I use this to familiarize myself with the subject and use it to paint my grisaille from. I always use a grisaille for portraits. I usually draw on a cool toned canvas (a mix of flake white, ivory black, and yellow ochre) with warm paint (burnt umber) and keep the shadows warm and thin. I then block in the lights using a cool grey mixture (In this case, green umber and white) and try to lay on a good amount of paint to give it body. I will let this dry thoroughly before adding color. I begin the color stages by oiling in with a warm glaze. In this case raw sienna. I apply it all over the entire portrait. I then use a basic cool flesh mixture of Flake White, Calcite, Iron Oxide, a touch of Vermillion and a touch of Cobalt Blue, The idea is to paint the cool flesh color into the warm glaze. I continue to apply the flesh colors relatively translucently. I want to leave the shadows warm and transparent, the mid tones I want relatively thin, letting the grey of my grisaille show through, and the lights thickly and opaquely. I will add a bit of egg yolk to my Flake white in the opaque passages to add some body and texture. I continue to model forms adding colors to my flesh mixture as needed. I do keep a few things in mind when adding color. I am using what some painters call color bands. That means keeping the tones in the forehead more yellow, and the area across the middle of the face more red because of the presence of blood-vessels. I also want to flesh tones to be cooler and the shadows warm as is the case when painting in natural light. When starting a second sitting with color after the previous layer is dry, I start by oiling in and then applying a yellowish glaze to the forehead and a reddish glaze over the middle of the face. Then using my flesh mixture and pure colors I continue trying to build form and add texture in the lights, but trying to keep the grisaille showing through in the half tones as much as possible. I really try to be mindful of the individual forms of the face and give them some dimensionality. It doesn’t always work out so well, but that’s the idea. The process shots were taken with my camera so a lot is lost, but I hope you can see the basic idea.