[vimeo]http://vimeo.com/34474615[/vimeo]
This is one of those topics that often gets ignored by a lot of instructors and books. Really take some time to think about the idea of contour lines and how your eye reads form. These lines are often referred to as isolines. They help the viewer understand how light should travel across the surface of your form. These curves, when modeling, will help you have a better understanding of how curves ultimately act as the “cage” that contains your surfaces.