Whether drawing realistic ... the darker the shading. Alternatively, try building tone using several layers of pencil, using softer pencils or working with charcoal.

Charcoal is a fast and responsive drawing media ... They are like pencils, but without the wooden casing. They are useful for shading and blending.

(I leave out powder shading and charcoal shading ... Experiment with different drawing mediums such as graphite pencils, charcoal, and ink to discover which medium resonates with you the most.