Artwork: Julia Barinova
These exceptional examples of three dimensional drawing are done in pencil. Such artwork requires a mastery of visualizing where light would hit the drawn objects, as those parts should be shaded lightly or not at all. The places that would not be lit would be more heavily shaded. Additionally, the artist will sometimes insert actual objects into their drawing, such as a pencil or even their hand. Actual three dimensional objects interacting with the drawing enhances its three dimensionality.
See more examples of excellent three dimensional drawings here.