Time to talk about more fundamentals. (never get tired of those , because we all need to remember this stuff and use it in our work) .
Ace storyboard artist Sherm Cohen has posted some good stuff about Line-Of-Action, Contrasting Shapes, Silhouette, and all that jazz on his blog Cartoon Snap :
Take a look . Good examples of these foundational principles.
(click image to view it larger. More images on Sherm's blog.)