I've been working in my mixed paper sketchbook no 28 and this page is a Fabriano pastel paper. I have used a Faber Castell oil based sanguine pencil, which is like a conté pencil but less dry and crumbly and holds a good point.
I made a tracing from the photo and transferred it to the page using a sheet of Saral wax free transfer paper. I only drew the barest essential outlines so that the features are in the correct places.
I always start with the eyes as they can make or break the drawing. For the iris I draw a tiny circle around the white highlight to make sure it is reserved, then the pupil line followed by the outline of the iris and start to shade it in. If you make the highlight circle a bit larger than in the photo you've got a margin of error if you make a mistake as it's impossible to get back to the white paper once you've drawn on it.
At this stage it is important to use lightly drawn lines so that you're not committing too much before you have a whole picture to work on. For the mouth I only suggest the teeth as they can look very ugly if you try to draw the gaps and shadows.
I started on the hair which in this case was quite difficult as it seems to grow in lots of directions! The main idea is to depict the shapes and shadows rather than individual hairs except on the forehead. I also drew a line around the edge as I wanted to show that he was cropped by the photographer and I didn't quite know what the hair did in the unseen parts of the portrait. I also think it helps to make the image more interesting if there is an area going off the side of the picture.
Next I tackled the shading using the side of the pencil very lightly, gradually building up the tones.
This shading takes a while as it's very easy to overdo it but you can lift off if necessary using a putty rubber which you just dab on carefully instead of rubbing as you would with a plastic eraser.
Go over the portrait carefully with the pencil till you're happy with it, I very carefully put in the shadows in the corners of the eyes to make them look right and to keep the whites next to the iris as bright as possible. I've only suggested the gap between his front teeth although there is a bigger darker one there really.
This is as far as I went with the portrait and I'm quite happy with it, it's quite a good likeness if you compare it with his photo below.
I'm working on another version now but it's not ready to share as I want to take my time and do something a bit different. This single colour sketch is a good practise run to get my eye in for any potential difficulties later.