Getting Started

For this exercise you will need a subject - an old jug - and a light source, such as a window or lamp. Light coming from one direction will give you good shadows to work with. Any charcoal will do, though different types will give slightly different results. Use a basic charcoal pencil. You'll need a eraser, a piece of rag for blending, and a paper stump if you have one (or just twist the corner of the rag into a point).

Starting in the Middle

For this drawing, we start 'in the middle', with a mid-value layer of charcoal. By starting with a middle value and using an eraser to subtract the lighter shades and highlights, you train your eye to look for highlights. This helps you to think of them in terms of areas of value in their own right, and not just the white paper 'left behind' during drawing.
Beginning with a darker value base also encourages a better range of tonal values, as you don't have the expanse of white paper that makes even light lines seem strong. It is less daunting to make a dark mark when there is already some tone on the page.
Apply the charcoal lightly and evenly, gradually building up a smooth even layer of tone, working in a variety of directions to even out the texture as much as possible. You can use a rag to gently blend it, but don't apply too much pressure - you don't want to push the particles into the paper fibers, as this will make it hard to erase.

Blocking in the Form

The next stage of drawing can progress very rapidly. Observe your subject as a 'whole', mentally noting the overall shape and the main areas of light and dark. Visualize the placement of the object on the page and rough in the darkest areas of the form, avoiding outlining. Think in terms of large areas of tone. Use your eraser to lift off charcoal on the lighter areas of the form and background; very quickly the shape begins to emerge.

Developing the Form and Graduating Values

Use a rag and blending stump to smooth areas of tone. (A rag will lift some tone, while the stump will blend without lifting much). Draw back into the darker areas, adding some definition. Don't neglect the background. This example has a relatively light background. A darker background can look very effective, as it allows you to create a more dramatic chiaroscuro effect.

Completing the Drawing

Roll a corner of your eraser into a point, and use it to draw precise highlights - here, the lip of the jug, and the edge of the handle, as well as the line around the neck of the jug. The background has been heavily erased, and shadows added. Note how black some of the dark areas are - don't be tentative with your charcoal - take advantage of those velvety darks for a dramatic effect.