The best place to start is with a simple beginning. Let's look at what I am trying to draw to begin with. (See Picture)
I probably will not use the hand in this one though, in order to concentrate on the proportions and shadow rendering, and I will use a different hairstyle just for fun. The idea is not to make an exact copy, but a nice personal interpretation. This is step one:
In order to see it better I suggest you download it to your computer, or at least click on "view" in your browser and select the "full screen" mode. The two dots at top is the space between the eyes, the dot below it is the length of the nose at the tip, and the dot on the bottom here is the mouth line at the bottom of the upper lip. The eye corners are less than at the halfway place on the paper and her head is slightly tilted down in relation to the viewpoint which is why I only used one dot for the base of the nose rather than two. The paper I am working on is a regular size of 8 1/2 by 11 inches. I intend to show the points, and lines, then shadows, forms, and texture: one step at a time so you can see my approach. I would like to emphasize that I am not saying that this is the only approach, or even the only approach that I would use. This is just one way of doing it.
This lesson is continued in Draw a Face with Dots 3 2.