Rough, gesture, or action sketches are usually rendered very quickly, sometimes in less than a minute. The benefits of making rough sketches are in the process, rather than the creation of a magnificent work of art. Hence, you only goal is to capture a mood, expression or gesture on your drawing paper.
This tutorial contains very useful tips about sketching different poses and figures. It also explains the basic sketching process, and teaches you how to examine sketches and choose models.