TRSE: How To Draw Tutorials:
The Basics of 3D Drawing

    Whenever you draw a character, the clothing should not use straight lines because of the way the entire body (head, arms, legs,) are curved. Even watches/braclets have to go around your wrists while the beltlines go around your hips/waists. Look at the diagram above and see how everything are drawn in forms of cylinders, cones, and spheres or more appropriately "bubbles" as some artists call them. One side of the face and body is always wider than the other side when viewed at such angled perspectives. You don't have to draw everything in such 3D shapes, but there are few things you can add to make your drawings seem 3D.
    When you draw any clothing, all you do are add the "crescents" or arcs to give various parts of the body look bit more 3D. You don't really want your drawings to look flat or boxy. ^_^

    This is another example of how everything should look in 3D. Since everything shrink over the distance until they disappear which is the limit of how far we can see. The characters in foreground always seem bigger than those in the background and even the trees and sidewalks shrink over the distance. The castle being so far away looks very puny even it's far bigger than any people. When Muneca (one with hat) expands her finger to point, it seems to get bit bigger. Now look at the spikey-haired man (Bismun) reading the newspapers. Whenever the newspapers are held up, few extra pages should be visible and the pictures on the newspapers should be parallel to the newspapers' edges so to make it seem 3D. I must point out that this kind of diagram works only if the ground/floor is FLAT, and it can get more complicated if the ground is not quite flat... (think of hills and mountains...)
    It takes a great deal of experimenting(playing) to figure out how to draw in 3D and that is something you can give a try when you're ready to do so. To learn to draw anything, you have to watch what you're drawing and keep your brains active! Let's move on to learn about how to draw a Chibi-character in the "Above" Point of View which may help you have a better grip on the 3D concept.