Elements of Design

The Element of Design include the following:
LINE
Line can be considered in two ways. The linear marks made with a pen or brush or the edge created when two shapes meet.
SHAPE
A shape is a self contained defined area of geometric or organic form. A positive shape in a painting automatically creates a negative shape.
DIRECTION
All lines have direction - Horizontal, Vertical or Oblique. Horizontal suggests calmness, stability and tranquillity. Vertical gives a feeling of balance, formality and alertness. Oblique suggests movement and action
SIZE
Size is simply the relationship of the area occupied by one shape to that of another.
TEXTURE
Texture is the surface quality of a shape - rough, smooth, soft hard glossy etc. Texture can be physical (tactile) or visual.
COLOUR
Also called Hue
VALUE
Value is the lightness or darkness of a colour. Value is also called Tone

And the Principles of Design include:
BALANCEBalance in design is similar to balance in physics
GRADATIONGradation of size and direction produce linear perspective. Gradation of of colour from warm to cool and tone from dark to light produce aerial perspective. Gradation can add interest and movement to a shape. A gradation from dark to light will cause the eye to move along a shape.
REPETITIONRepetition with variation is interesting, without variation repetition can become monotonous.
CONTRASTContrast is the juxtaposition of opposing elements eg. opposite colours on the colour wheel - red / green, blue / orange etc. Contrast in tone or value - light / dark. Contrast in direction - horizontal / vertical.
The major contrast in a painting should be located at the center of interest. Too much contrast scattered throughout a painting can destroy unity and make a work difficult to look at. Unless a feeling of chaos and confusion are what you are seeking, it is a good idea to carefully consider where to place your areas of maximum contrast.
HARMONY
Harmony in painting is the visually satisfying effect of combining similar, related elements. eg.adjacent colours on the colour wheel, similar shapes etc.
DOMINANCE
Dominance gives a painting interest, counteracting confusion and monotony. Dominance can be applied to one or more of the elements to give emphasis
UNITY
Relating the design elements to the the idea being expressed in a painting reinforces the principal of unity.eg. a painting with an active aggressive subject would work better with a dominant oblique direction, course, rough texture, angular lines etc. whereas a quiet passive subject would benefit from horizontal lines, soft texture and less tonal contrast.

Of these design concepts, the above picture reveals evidence of several principles and elements. The line is reinforced throughout the scheme in a horizontal manner, creating a pleasing look. The balance of the room and furniture arrangement also reinforces the strengths of the principles of design. The contrast of the colors create emphasis on the chairs and fireplace, the key functions of this area. All of these elements that are applied help add to the unity and harmony of the space. These tools are vital for a designer to enforce due to the affective projects that they produce. Without the use of these tools, chaos and clutter is sure to occur.

Definitions courtesy of http://www.johnlovett.com/test.htm