There are some main basic principles for design:
Balance is an equilibrium that results from looking at images and judging them against our ideas of physical structure (such as mass, gravity or the sides of a page). It is the arrangement of the objects in a given design as it relates to their visual weight within a composition. Balance usually comes in two forms: symmetrical and asymmetrical.
Rhythm is the repetition or alternation of elements, often with defined intervals between them. Rhythm can create a sense of movement, and can establish pattern and texture. There are many different kinds of rhythm, often defined by the feeling it evokes when looking at it.
Regular: A regular rhythm occurs when the intervals between the elements, and often the elements themselves, are similar in size or length.
Flowing: A flowing rhythm gives a sense of movement, and is often more organic in nature.
Progressive: A progressive rhythm shows a sequence of forms through a progression of steps.
Proportion is the comparison of dimensions or distribution of forms. It is the relationship in scale between one element and another, or between a whole object and one of its parts. Differing proportions within a composition can relate to different kinds of balance or symmetry, and can help establish visual weight and depth. In the below examples, notice how the smaller elements seem to recede into the background while the larger elements come to the front.
The concept of unity describes the relationship between the individual parts and the whole of a composition. It investigates the aspects of a given design that are necessary to tie the composition together, to give it a sense of wholeness, or to break it apart and give it a sense of variety. Unity in design is a concept that stems from some of the Gestalt theories of visual perception and psychology, specifically those dealing with how the human brain organizes visual information into categories, or groups2.