It is useful to remember that there are many theories that deal with design and aesthetics. While each has its own system of dividing the area of frame and or giving importance to certain areas in relationship to others - none offer an absolute system of image design that guarantees a perfect image. When we take photographs or make images we tend to apply them instinctively. Knowing what they are, how they work allows us to apply them in this intuitive manner.
The Golden Mean
Some design theories, like the golden mean or golden section date back to the ancient Greeks.
Their architecture and other arts were based on base on certain proportions.
1 : 1,618 or The Golden Mean
The 1,618... is an irrational number; its exact description is 1 + (√5 - 1) / 2
The golden mean generates spirals, as can be seen in the diagram at the bottom:
An interesting reference is that the Egyptian hieroglyph of Aries is a spiral and the god that goes with it is CHNOUM, the ram-headed god and the Greek counterpart is Ares and PALLAS ATHENE.
Examples in Architecture
As the drawings and inscribed ratio's indicate, the Parthenon is built according to the Golden mean ratio’s. Only the inner chamber at the back is of an 1 : √2 ratio.