Hieros Gamos, Fakemon and More

[Chris2Balls [:B]]

i don't really understand what you mean, but visualising your model in three dimensions in your mind's eye certainly helps pin down the shading. this is actually why i personally have difficulties doing some of my pieces.
what helm's done in the image you've posted is fragmented a man's head into a simplified blunt volume. this type of picture is good to practice creating lightsources on, since you're basically filling the faces and the edges with a value.
drawing your model in several different angles helps you visualize it in three dimensions (if you do four drawings from the front, the back and the sides for example, or several views from 3/4, etc).