“Charcoal pencils are great for adding details into your drawing. You can buy them in soft medium and hard. The soft ones are the easiest ones to use. I find that the hard ones are sometimes too stiff and scratchy.
Sharpening a charcoal pencil can be tricky because the charcoal inside the pencil is really fragile and breaks easily. You don’t want to use a manual pencil sharpener and, you also don’t want to use an electric pencil sharpener. In both instances the charcoal almost always breaks.
You want to use a utility knife or a razor blade, but make sure if you use a utility knife that you don’t use it like this; not only is the charcoal pretty much guaranteed to break, but you’ll probably slash anybody who’s standing nearby.
Instead, you want to position your thumb behind the blade and, use your thumb to gently push the blade upwards to carve out the wood surrounding the charcoal and, then leaving the charcoal intact.
Keep in mind that charcoal pencils don’t erase easily so, they’re no good in the beginning part of the drawing when you want to make a lot of mistakes and erase a lot of areas. Make sure that your charcoal pencil is always late to the party. At the end of the drawing it can help you articulate many details.”