Balance

Equilibrium: The pleasant arrangement of elements in a composition.

Equilibrium is what can make or ruin a composition.

Imbalance: A composition without equilibrium.

Unbalanced compositions often create an uneasy feeling in the watcher.

Symmetry: When an object's side is the same as the other side.

The right side of this spider is a reflection of its left side and vice versa.

Rhythm

Kinesthetic Empathy: Process in which the viewer recreates an action and/or sentiment when she/he observes.

(Work in Progress)

Rhythm: Element of design based on the repetition of motifs.

Mere visuals can create such sentiments that can soothe or unease our mood,

Progressive Rhythm: The gradual change of a motif in a regular pattern.

This kind of rhythm builds up until it achieves a climax, or an anti-climax.

Scale and Proportion

Proportion: The size of a specific element compared to another one

This are the proportions of a human male.

Hieratic Scaling: Composition in which the hieratic position of an element determines its size.

You can clearly see that the leader of this gang is the big guy.

Surrealism: Style of art that expresses ideas in a fantastic and irrational way.

This image expresses a shape and form that can't be placed on the real world.

Unity

Harmony: The pleasing balance of elements in a composition.

Harmony is created when everything rests at the right place.

Repetition: Re-using the same element over and over again in a composition.

Multiple image can be a form of repetition

Continuation: A line that continues from one shape to another and allows the eye to flow smoothly throughout the composition.

Trying to follow through the body of this lung dragon is an example  of continuity.

Emphasis and Focal Point

Emphasis by Contrast: Emphasis achieved by changing the color, value or color-intensity of the area meant to be the focal point.

A change of hue, value, or intensity can create emphasis by contrast. 

Emphasis by Isolation: Emphasis created by separating an object from a group to draw more attention to it.

Separating one or some from a group calls our attention. This image shows emphasis by contrast and by isolation.

Emphasis by Placement: When the focal point is located in the center or the near-the-center area of a composition.

Even though it is showing multiple subjects, the one in the center calls our attention more than the others.

Color

Primary Colors: The base of all colors.  In the additive color system (it uses light) the primary colors are: Blue, Red, and Green. In the subtractive color system (it uses pigment) the primary colors are: Blue, Red, and Yellow.

RGB color scheme. From the additive system, if they are all mixed they create white.

Primary colors in the subtractive system, if they are all mixed they create black.

Complimentary colors: Opposite hues in the color wheel. They accentuate each other side to side, and they neutralize each other if combined.

The primary colors are to the left, and it's complimentary to the right. Yellow - Violet, Blue - Orange, and Red - Green.

Optical Mixture: Mixture of colors created by the eye when a pattern of color is close together.

The colors at the sides seem more clear than the colors at the top of the cube, even though they are the same.

Value

Achromatic:  A- meaning "without", chroma- meaning "intensity of color". Without hue (Blacks, grays, and whites).

Midtones, shadows and light were used to create this composition. 

There's value but there's no hue.

Chiaroscuro: Italian word for the technique of using shadows and light. to create depth.

Chiaroscuro is just a fancy word to express the use of value to crate a 3-D object in a 2-D space.

Cross-Hatching: technique of adding depth to a composition that uses lines to add value.

The neck, tail, and back limbs are the areas where cross-hatching is seen the clearest.

Illusion of Motion

Anticipated Movement: The Implication of movement by the viewer's past experience with similar situations.

This Knight is about to attack as it can be seen by it's pose.

Repeated Figure: A device where a character appears in different posses within the same composition to illustrate movement.

This little comic strip illustrates a character jumping from a building and impacting the ground with force.

Multiple Image: A device used to imply movement by slightly overlapping a character over itself within the same composition.

The character in this picture is falling from the sky and breaking his fall with a  somersault. 

Illusion of Space

Overlapping: a device that adds depth to a picture by layering shapes into one another.

Quack! The front duck is overlapping the back one.

Aerial Perspective: A phenomenon that makes shapes far away to look without contour, less colorful and fuzzy.

The mountains seem washed away as they recede .

Linear perspective: It is a phenomenon that makes parallel lines intersect as they recede.

This railroad tracks intersect at some point far away, even though the metal bars are parallel  to each  other.

Pattern and Texture

Pattern: it is a repetition of design.

The lines in this notepad show a pattern.

Impasto: technique of creating an irregular paint surface using thick pigment.

The white paint in this picture creates an uneven surface.

Visual Texture: It is the illustration of a texture.

The roughness of the scales on this dragon make it look more realistic.

Shape

Naturalism: Is the representation of believable compositions.

This dragonfly's anatomy is plausible, even though it is floating in the emptiness of the page.

Abstraction: It is the simplification of shape to its core, and it doesn't show much detail.

This duck is composed of  lines of yellow paint and the background is composed of blue brushstrokes.

Curvilinear shape: a shape composed of curves.

This car is composed of complicated curves, it has a curvilinear shape.

Lines

Line: Paul Klee defined a line as a "point set in motion"

http://nowiknow.com/making-it-rain/
Rain is a lot of points(water droplets) set in motion by gravity

Implied Line: a line created by the eye while following a set of points, objects, figures, shapes, etc.

The landing lights create an implied line.

Psychic Line: It is a non-existent line, created sub-consciously.

A psychic line is created when we look to the left to know what the dragons are staring at.