Here is a series of photos of a painting in progress, at least with the method I'm using right now. To start with, I've toned the panel with a bit of color and blocked in the drawing as a guide.
Next I blocked in the basic colors I want to use and tried to get close to the values I want for the skin, hair and background.
Here I added in some details and refined the drawing more.
And last is obviously finishing details and making final adjustments to the color. This is an imitation of a painting by the incredible Malcolm Liepke.