Principles
The principles of design combine the elements to create a composition, they are the guidelines used to arrange the elements. Each principle is a concept used to organize or arrange the structural elements of a design and it applies to each element of a composition and to the composition as a whole. Again, without turning to a specific discipline, we can say that the basic Design Principles are composed by:
Balance
Balance is the concept of visual equilibrium of similar, opposing, or contrasting elements that together create a unified whole. It refers to the appropriate arrangement of the objects in a design to create the impression of equality in weight or importance. It comes in 2 forms: Symmetrical (when the weight of a composition is evenly distributed around a central vertical or horizontal axis) and Asymmetrical (when the weight of a composition is not evenly distributed around a central axis).
Emphasis
It marks the location in a composition which most strongly draw the viewer attention, it is also referred as the focal point. It is the most important area or object when compared to the other objects or areas in a composition. There are three stages of emphasis, related to the weight of a particular object within a composition: Dominant (the object with the most visual weight), Sub-dominant (the object or element of secondary emphasis) and Subordinate (the object with the least visual weight, which is usually the background).
Movement
Is the visual flow through the composition, where (depending on the elements placement) the designer can direct the viewer´s eye over the surface of the design. The movement can be directed along edges, shapes, lines, color, etc and the purpose of movement is to create unity with eye travel. By arranging the composition elements in a certain way, a designer can control and force the movement of the viewer’s eyes in and around the composition.
Pattern
An object or symbol that repeats in the design is a pattern. It can be a pattern with a precise and regular repetition or an alternate pattern, which uses more than a single object or form of repetition. We can say that is simply keeping your design in a certain format.
Repetition
Repetition creates unity and consistency in the composition; it is the reuse of the same, similar or different objects throughout the design. The repetition can be irregular, regular, uneven or even and can be in the form of Radiation (where the repeated elements spread out from a central point) or Gradation (where the repeated elements become smaller or larger). It often works with a pattern to make it seem active and along with the Rhythm helps to create different types of it.
Proportion
Proportion is the comparative relationship in between two or more elements in a composition with respect to size, color, quantity, degree, etc, or between a whole object and one of its parts. The purpose of the proportion principle is to create a sense that has order between the elements used and to have a visual construction; and it can occur in two ways: Harmonious (when the elements are in proportion) or Unbalanced (when the disproportion is forced).
Rhythm
Rhythm is the alternation or repetition of elements with defined intervals between them, it creates a sense of movement and it is used to establish a pattern and/or a texture. There can be 3 different types of rhythm: Regular, Flowing or Progressive. The Regular rhythm occurs when the intervals between elements are similar, the Flowing rhythm gives a sense of movement while the Progressive rhythm shows a sequence of forms through a progression of steps.
Variety
Variety is the principle that refers to the combination of elements in an intricate and complex relationship using different values, lines, textures, shapes, hues, etc. It is complementary to unity and often needed to create visual interest or to call the attention to a specific area in the composition.
Unity
Unity it is used to describe the relationship between the individual elements and the whole of a composition (which creates a sense of completeness, that all of the parts belong together) and it is a concept that comes from the Gestalt theory of visual perception and psychology. Three of the most well-known concepts of this theory are the Closure (is the idea that the brain tends to fill in missing information when it perceives an object is missing some of its pieces), Continuance (is the idea that once you begin looking in one direction, you will continue to do so until something more significant catches your attention) and Similarity, Proximity and Alignment (is the idea that elements of similar size, shape and color tend to be grouped together by the brain).
Examples
In the following quick examples, you may notice how the Elements and Principles of Design are combined. The following examples do not pretend to be a complex explanation of the multiple possible combinations, but to serve as an easy visual example of how the elements and principles work together.