After transferring the drawing I lightly block in the areas where there will be highlights and make sure everything has been transferred and all the muscle masses are well defined and easy to see and exactly how I want the line drawing.
Being right handed I work from left to right when putting the shading onto a drawing. It prevents my hand running across graphite already laid down on the paper and smearing it across the drawing which will need to be erased afterward and can cause the sharpness of the drawing to be lost.
I find that a mechanical pencil works best for me, as it always has a sharp point and I do not have to take the time to stop and sharpen the point as I would have to do with a regular wood encased graphite pencil.
I start with the darkest shadows on the tail and put down my first layer as a mid tone. With each layer I continue to go over the one laid down before, gradually building up a darker value in the shadow, and each successive layer until I reach the mid tone layer of the tail.
By this point my darkest values are well established with up to four layers of graphite.
Now I start working into the lighter tones always being careful to leave the highlights as the white paper showing through without any graphite on it.
I continue to work the layers over the tail until the lightest tones have been put down.
After carefully removing any loose graphite from the drawing I will lightly spray it with a fine layer of workable fixative.
