Design elements and principles describe fundamental ideas about the practice of good visual design that are assumed to be the basis of all intentional visual design strategies.
The elements form the 'vocabulary' of the design, while the principles constitute the broader structural aspects of its composition.
Awareness of the elements and principles in design is the first step in creating successful visual compositions.
These principles, which may overlap, are used in all visual design fields, including graphic design, industrial design, architecture and fine art.
Design is the organized arrangement of one or more elements and principles (e.g. line color or texture) for a purpose.
The secret of great design in the classical arts is the 'Sectio Aurea'

The Sectio Aurea

Two quantities are in the golden section (Latin: sectio aurea) if the ratio of the sum of the quantities to the larger quantity is equal to the ratio of the larger quantity to the smaller one. The golden ratio is an irrational mathematical constant, approximately 1.6180339887.

At least since the Renaissance[citation needed], many artists and architects have proportioned their works[citation needed] to approximate the golden ratio—especially in the form of the golden rectangle, in which the ratio of the longer side to the shorter is the golden ratio—believing this proportion to be aesthetically pleasing.
Mathematicians have studied the golden ratio because of its unique and interesting properties. The golden ratio is also used in the analysis of financial markets, in strategies such as Fibonacci retracement.

The Construction of the Golden Rectangle

Mathematician Mark Barr proposed using the first letter in the name of Greek sculptor Phidias, phi, to symbolize the golden ratio.

The Golden Section applied to the front elevation of the Jefferson Memorial

'Vitruvian Man'

Related to the sectio aurea, as an aid to classic design, is Leonardo's 'Vitruvian Man'.
The Vitruvian Man is a world-renowned drawing created by Leonardo da Vinci around the year 1487.
It is accompanied by notes based on the work of the famed architect, Vitruvius.
The drawing, which is in pen and ink on paper, depicts a male figure in two superimposed positions with his arms and legs apart and simultaneously inscribed in a circle and square.
The drawing and text are sometimes called the Canon of Proportions or, less often, Proportions of Man.
The drawing is based on the correlations of ideal human proportions with geometry described by the ancient Roman architect Vitruvius in Book III of his treatise De Architectura.
Vitruvius described the human figure as being the principal source of proportion among the Classical orders of architecture.

Relief based on the Vitruvian Man