Basic Shapes
There are four basic shapes, and it is possible to draw any object, regardless of it's complexity, by employing said shapes. The cube, the cylinder, the sphere, and the cone are the basic forms you may combine to achieve a desired structure. When combining shapes, pay particular attention to position and scale.

The illustration below is an example of how to
construct an object using basic shapes.












The Ellipse
There is a fifth basic shape, which is really a modification of the sphere, which is called an ellipse. In geometry, an ellipse (from the Greek elleipsis, a "falling short") is a plane curve that results from an intersection of a cone by a plane in a way that creates a closed curve. Circles seen in perspective are ellipses, or flattened spheres. You will encounter ellipses often, they are an integral part of drawing from observation, showing depth and conveying perspective. And remember, circles don't have corners, therefore ellipses should not come to a point on either side.