I paint the eyes first. Since, for me this is the most difficult area of the face to paint. That way, if I screw them up I can repaint them without having to worry about the rest of the face. After the eyes are finished, I paint on the acrylic undercoat. I then paint an overall oil base color, followed by: shadows, deep shadows, highlights, light highlights. This is all painted wet on wet and blended after each step. After the face is completely dry, I repaint the deepest shadows and lightest highlights. The last things I paint are the lips and eyebrows.