Foreshortened arm, done in pencil. 

Full body sketch of a model, done in pencil.

Profile sketch of a model in a resting pose, done in pencil. 

Duplicate of the sketch above, but done again with shading.

One-line contours of a posing model, done with ballpoint pen. 

5 minute one-line contours of a posing model, done with ballpoint pen.