This is where I'm at, after about 5 days of planning and decision-making, and 2 days of sketching and drafting. Once again, I am working on a large portrait which doesn't fit onto my drafting table, so I have trimmed it where I can to prevent damage to the paper.
The first stage of the drawing process was to draft the main features of the composition, lightly with a hard pencil. I don't worry about fine details, at this point, as my principle goal here is to get the proportions right. With this in mind, I map out the light and dark areas, and outline the main features. On the face, I locate the position of the features and the shadowed areas, but I don't worry about achieving a likeness or producing good art, at this stage.
Here, you can see the outline of the entire composition (though it's not a good photo!). This has been drafted lightly with an HB pencil so that it can be erased easily, later. Coloured pencils are mostly transparent so any initial markings will need to be removed to prevent them showing through the final drawing.
Now, it is time to begin the exciting details! First of all, I carefully erase the pencil lines of the face and replace them with a light sand colour, which will blend in with the layers that I will be applying next. Then, I begin rendering the eyes. Although this is a large picture, the face is quite a small part of the composition and the detail of the eyes is not easy to see. Because accurate rendering of the eyes is crucial to achieving a likeness, I enlarged the photo as much as I could on the computer and alternated between my computer screen and the reference photos as I worked. Normally, I think that art succeeds best when it simplifies reality so I try not to get obsessive about tiny details, but, with facial features, fine details can be the difference between successfully capturing a subject and falling crucially short.
Tomorrow, I will continue to render the features, before applying the many layers that it takes to build up a believable skin tone.