emphasis.

Emphasis:  Emphasis is a principle of art which occurs any time an element of a piece is given dominance by the artist. In other words, the artist makes part of the work stand out, in order to draw the viewer's eye there first.
    This photo achieves the principle of  design because the red dot stands out from all the black and white circles.












Horizontal lines:a constructive line, either drawn or imagined, which passes through the point of sight, and is the chief line in the projection upon which all verticals are fixed, and upon which all vanishing points are found.
This photo achieve the principle of design because the lines are going east and west

Repetition/ pattern:Repeating visual elements such as line, color, shape, texture, value or image tends to unify the total effect of a work of art as well as create rhythm. Repetition can take the form of an exact duplication (pattern), a near duplication, or duplication with variety.
this photo achieve the principle of design because the pattern is the same for everything

Birds eye view: is an elevated view of an object from above, with a perspective as though the observer were a bird, 

this photo achieves the principle of design because the picture is taken from above so you are looking down at the baby.

Vertical lines:positioned up and down rather than from side to side : going straight up

this photo achieves  the principle of design because the lines are running north and south.

Texture:is used to describe either the way a three-dimensional work actually feels when touched, or the visual "feel" of a two-dimensional work.

this photo achieves the principle of design because the appearance and feel of the surface is marbles 

symmetrical balance:all of the subjects in the photo are either symmetrical or asymmetrical. Symmetrical balance, or formal balance, occurs when all of the objects in the photograph are placed on either side of a specific point essentially mirroring its own shape. Asymmetrical balance occurs when one or more objects that contrast one another are balancing either side of a specific point.

This photo achieves the principle of design because the ones side of the city balances/mirrors the other side.

Unity:occurs when all of the elements of a piece combine to make a balanced, harmonious, complete whole. Unity is another of those hard-to-describe art terms but, when it's present, your eye and brain are pleased to see it.

This photo achieves the principle of design because the elements (crayons) are all combined together.

Rule of thirds:The rule of thirds is a "rule of thumb" or guideline which applies to the process of composing visual images such as designs, films, paintings, and photographs.

this photo achieves the principle of design because the whole image is divided into equal parts.

Diagonal lines:
generally work well to draw the eye of an image’s viewer through the photograph. They create points of interest as they intersect with other lines and often give images depth by suggesting perspective. 
This photo achieves the principle of design because the black and white lines are running slanted.

Variety:Differences achieved by changing elements in a composition to add interest.
Weaving: A process and product created by interlacing strands of material.
This photo achieves the principle of design because the colors in the image give interest to the composition 

Simplicity: The property, condition, or quality of being simple or uncombined

This photo achieves the principle of design because the apple is singled out with the background.

Asymmetrical Balance: design is typically off-center or created with an odd or mismatched number of disparate elements. When the left and right sides of the design are unequal it is said to have asymmetrical balance.

This photo achieves the principle of design because the door and the window balance each other out.

Movement: a movement in which some elements recurs regularly.  Like a dance it will have a flow of objects that will seem to be like the beat of music.

Rhythm:is the path the viewer’s eye takes through the artwork, often to a focal area. It can be directed along lines, edges, shapes and color. Movement is closely tied to rhythm.

This photo achieves the principle of design because the girl shows action and the path of
the viewers eye through it.

Proportion and scale:refers to the correction depiction of the all the parts related to each other in a shape/form within a realistic painting or drawing.  Proportion lends a sense of balance and harmony to a piece of artwork.  One may decide to distort the proportions within an artwork to create a certain effect on the viewer. 
This photo achieves the principle of design because the one object is relating to another.


 Horizon line:

The horizon line is a line drawn across a picture.  It is essential for a picture to have a horizon line if a person wishes to communicate from what perspective a person is observing the picture (from above an object, below an object…etc).   It is not necessary to include the horizon line in the picture.  However, it is important to include a ‘virtual’ horizon line in order to make a picture follow correct perspective.  The horizon line is always one’s eye level.  If one draws a line perpendicular to the ground outwardly from one’s eye level, this is what is considered the horizon line. this photo achieves the principle of design because the sky  meets the ground. worms eye:is a view of an object from below, as though the observer were a worm; the opposite of a bird's-eye view. A worm's eye view is used commonly for third perspective when you put one vanishing point on top, one on the left, and one on the right. this photo achieves the principle of design because the building is up above Framing:In visual arts including cinematography, framing is a technique used to focus the viewer's attention upon the subject. Framing can make an image more aesthetically pleasing and keep the viewer's focus on the framed object this photo achieves the principle of design because the viewers attention is to the forest becasue of the windows. curved lines:lines that deviate from straightness in a smooth fashion this photo achieves the principle of design becase the lines deviate