Step 1 - The Drawing
I always avoid using charcoal or regular graphite pencil, as the eraser/corrections would give a messy look to the surface. Instead, the drawing will be executed using a "sketch and wash"® pencil; it allows clean erasing using a damp piece of paper towel or even a cue tip. To refine the lines, a "Tuff Stuff"® eraser, which can be sharpened with a sharp blade as necessary.
The trick is to "build' the drawing carefully, starting with basic construction lines (see below), keeping the pencil sharp to avoid fat lines, and avoiding pressure on the pencil, which will give a light drawing, easy to correct.