It all begins with an understanding of the aspects that make up the three dimensional form. These elements are shape, space, value, texture, line, color, and time and movement. Each of these elements work together to make the form and create its ambiance. These are the elements that we, as artists and craftsmen, work with to create pleasing or meaningful objects in clay.
Design is all about using those three dimensional elements together to create a piece that holds together as a unit. Design grows out of and is infused by those elements. It is (or is best when) it is consciously understood.
One way to think about the distinction between the three dimensional elements and three dimensional design is to think about the difference between a tree growing in a field and a sculpture of a tree. The real tree is a three dimensional form and has all those elements present in its being. The sculpture, on the other hand, not only has those elements, but also used conscious design to make the sculptural tree have balance, visual rhythm, and proportion.
The precepts of three-dimensional design are the servants of three-dimensional art. They are used in the creation of artwork to inform or expound upon the purpose of that artwork.
The foundations of three dimensional art are subject matter, content, and form. In other words, what are we (the artist and audience) talking about; what does the artist have to say about the subject; and how does the artist use three dimensional design to say it.
Functional pottery, to be at its best, must also be created in accord with the elements of three-dimensional form and three-dimensional design. Within the overall form, functional pottery often has several different areas, such as the rim (aka lip), body (aka belly), and neck of a piece. Becoming consciously aware of these areas can help you create more pleasing pottery. It will also help you develop your own aesthetic or style in your work, simply by giving you a more concrete framework from which to launch your artistic "voice."
Functional pottery, especially that which has been thrown in the wheel, tends to fall into three categories as to overall shape. These are the cylinder, the disk, and the sphere. These overall shapes are modified by modifying the basic areas we talked of above. The transitions between areas can be sharply defined or very smooth and flowing.
In all cases, we again go back to the elements of the three-dimensional form and three-dimensional design. Although a pot may be physically balanced, if it is visually unbalanced it must likely will be left by the wayside. Creating pleasing functional pottery is as important as that pottery being able to fulfill its purpose.