In the visual arts, composition is the placement or arrangement of visual elements or 'ingredients' in a work of art, as distinct from the subject. It can also be thought of as the organization of the elements of art according to the principles of art.
The composition of a picture is different from its subject, what is depicted, whether a moment from a story, a person or a place. Many subjects, for example Saint George and the Dragon, are often portrayed in art, but using a great range of compositions even though the two figures are typically the only ones shown.
The term composition means 'putting together' and can apply to any work of art, from music to writing to photography, that is arranged using conscious thought. In the visual arts, composition is often used interchangeably with various terms such as design, form, visual ordering, or formal structure, depending on the context. In graphic design for press and desktop publishing, composition is commonly referred to as page layout.
The various visual elements, known as elements of design, formal elements, or elements of art, constitute the vocabulary with which the visual artist composes. These elements in the overall design usually relate to each other and to the whole art work.
The elements of design are:
Lines are optical phenomena that allow the artist to direct the eye of the viewer. The optical illusion of lines do exist in nature and visual arts elements can be arranged to create this illusion. The viewer unconsciously reads near continuous arrangement of different elements and subjects at varying distances. Such elements can be of dramatic use in the composition of the image. These could be literal lines such as telephone and power cables or rigging on boats. Lines can derive also from the borders of areas of differing color or contrast, or sequences of discrete elements. Movement is also a source of line, and blur can also create a reaction.
Subject lines contribute to both mood and linear perspective, giving the viewer the illusion of depth. Oblique lines convey a sense of movement and angular lines generally convey a sense of dynamism and possibly tension. Lines can also direct attention towards the main subject of picture, or contribute to organization by dividing it into compartments. The artist may exaggerate or create lines perhaps as part of their message to the viewer. Many lines without a clear subject point suggest chaos in the image and may conflict with the mood the artist is trying to evoke.
Straight left lines create different moods and add affection to visual arts. A line's angle and its relationship to the size of the frame influence the mood of the image. Horizontal lines, commonly found in landscape photography, can give the impression of calm, tranquility, and space. An image filled with strong vertical lines tends to have the impression of height and grandeur. Tightly angled convergent lines give a dynamic, lively, and active effect to the image. Strongly angled, almost diagonal lines produce tension in the image. The viewpoint of visual art is very important because every different perspective views different angled lines. This change of perspective elicits a different response to the image. By changing the perspective only by some degrees or some centimetres lines in images can change tremendously and a totally different feeling can be transported. Straight lines are also strongly influenced by tone, color, and repetition in relation to the rest of the image.
Compared to straight lines, curves provide a greater dynamic influence in a picture. They are also generally more aesthetically pleasing, as the viewer associates them with softness. In photography, curved lines can give graduated shadows when paired with soft-directional lighting, which usually results in a very harmonious line structure within the image.
There are three properties of color. Hue, brightness, and value. Hue is simply the name of a color, (red, yellow, and blue, etc.) Brightness refers to the intensity and strength of the color. The lightness and darkness to a color is the value. Color also has the ability to work within our emotions. Given that, we can use color to create mood. It can also be used as tone, pattern, light, movement, symbol, form, harmony, and contrast. 
Texture refers to how an object feels or how it looks like it may feel if it were touched. There are two ways we experience texture, physically and optically. Different techniques can be used to create physical texture, which allows qualities of visual art to be seen and felt. This can include surfaces such as metal, sand, and wood. Optical texture is when the illusion of physical texture is created. Photography, paintings, and drawings use visual texture to create a more realistic appearance. 
Lightness and darkness is what creates value in visual art. Value deals with how light reflects off of objects and how we see it. The more light, the higher the value. White is the highest or lightest value while black is the lowest or darkest value. Colors also have value, for example, yellow has a high value while blue has a low value. This is a very important element of design, especially in painting and drawing, to be able to create the illusion of light with contrast. Contrast is needed to understand two-dimensional artwork. 
The term form can be mean different things in visual art. Form suggests a three-dimensional object in space. It is also described as the physical nature of the artwork, such as sculptures. It can also be looked at as art form, which can be expressed through fine art. A form encloses volume, has length, width, and height, unlike a shape, which is only two-dimensional. Forms that are mathematical, a sphere, pyramid, cube, cylinder, and cone, are known as geometric forms. Organic forms are typically irregular and asymmetrical. This form can be found in nature, such as flowers, rocks, trees, etc., but can also be seen in architecture. 
Forms in drawing and painting convey the illusion of three-dimensional form through lighting, shadows, value, and tone. The more contrast in value, the more pronounced the three-dimensional form is. Forms with little value appear flatter than those with greater variation and contrast.
Space is the area around, above, and within an object. Photographers can capture space, architects build space, and painters create space. This element is found in each of the visual arts. It can be positive or negative, open or closed, shallow or deep, and two-dimensional or three-dimensional. In drawing or painting, space is not actually there, but the illusion of it is. Positive space is the subject of the piece. The empty spaces around, above, and within, is negative space.
The artist determines what the center of interest (focus in photography) of the art work will be, and composes the elements accordingly. The gaze of the viewer will then tend to linger over these points of interest, elements are arranged with consideration of several factors (known variously as the principles of organization, principles of art, or principles of design) into a harmonious whole which works together to produce the desired statement - a phenomenon commonly referred to as unity. Such factors in composition should not be confused with the elements of art (or elements of design) themselves. For example, shape is an element; the usage of shape is characterized by various principles.
Some principles of organization affecting the composition of a picture are:
The position of the viewer can strongly influence the aesthetics of an image, even if the subject is entirely imaginary and viewed "within the mind's eye". Not only does it influence the elements within the picture, but it also influences the viewer's interpretation of the subject.
For example, if a boy is photographed from above, perhaps from the eye level of an adult, he is diminished in stature. A photograph taken at the child's level would treat him as an equal, and one taken from below could result in an impression of dominance. Therefore, the photographer is choosing the viewer's positioning.
A subject can be rendered more dramatic when it fills the frame. There exists a tendency to perceive things as larger than they actually are, and filling the frame full fills this psychological mechanism. This can be used to eliminate distractions from the background.
In photography, altering the position of the camera can change the image so that the subject has fewer or more distractions with which to compete. This may be achieved by getting closer, moving laterally, tilting, panning, or moving the camera vertically.
There are numerous approaches or "compositional techniques" to achieve a sense of unity within an artwork, depending on the goals of the artist. For example, a work of art is said to be aesthetically pleasing to the eye if the elements within the work are arranged in a balanced compositional way. However, there are artists such as Salvador Dalí who aim to disrupt traditional composition and challenge the viewer to rethink balance and design elements within art works.
Conventional composition can be achieved with a number of techniques:
The rule of thirds is a composition guide that states that arranging the important features of an image on or near the horizontal and vertical lines that would divide the image into thirds horizontally and vertically is visually pleasing. The objective is to stop the subject(s) and areas of interest (such as the horizon) from bisecting the image, by placing them near one of the lines that would divide the image into three equal columns and rows, ideally near the intersection of those lines.
The rule of thirds is thought to be a simplification of the golden ratio. The golden ratio is thought to have been used by artists throughout history as a composition guide, but there is little evidence to support this claim.
The "rule of odds" states that by framing the object of interest with an even number of surrounding objects, it becomes more comforting to the eye, thus creates a feeling of ease and pleasure. It is based on the assumption that humans tend to find visual images that reflect their own preferences/wishes in life more pleasing and attractive.
The "rule of odds" suggests that an odd number of subjects in an image is more interesting than an even number. Thus if you have more than one subject in your picture, the suggestion is to choose an arrangement with at least three subjects. An even number of subjects produces symmetries in the image, which can appear less natural for a naturalistic, informal composition.
An image of a person surrounded/framed by two other persons, for instance, where the person in the center is the object of interest in that image/artwork, is more likely to be perceived as friendly and comforting by the viewer, than an image of a single person with no significant surroundings.
The rule of space applies to artwork (photography, advertising, illustration) picturing object(s) to which the artist wants to apply the illusion of movement, or which is supposed to create a contextual bubble in the viewer's mind.
This can be achieved, for instance, by leaving white space in the direction the eyes of a portrayed person are looking, or, when picturing a runner, adding white space in front of him rather than behind him to indicate movement.
Images with clutter can distract from the main elements within the picture and make it difficult to identify the subject. By decreasing the extraneous content, the viewer is more likely to focus on the primary objects. Clutter can also be reduced through the use of lighting, as the brighter areas of the image tend to draw the eye, as do lines, squares and colour. In painting, the artist may use less detailed and defined brushwork towards the edges of the picture.Removing the elements to the focus of the object, taking only the needed components.
In photography, and also (via software simulation of real lens limitations) in 3D graphics, one approach to achieving simplification is to use a wide aperture when shooting to limit the depth of field. When used properly in the right setting, this technique can place everything that is not the subject of the photograph out of focus.
A similar approach, given the right equipment, is to take advantage of the Scheimpflug principle to change the plane of focus.
Related to the rule of odds is the observation that triangles are an aesthetically pleasing implied shape within an image. In a canonically attractive face, the mouth and eyes fall within the corners of the area of an equilateral triangle. Paul Cézanne successfully used triangles in his compositions of still lifes. A triangular format creates a sense of stability and strength.
It is generally thought to be more pleasing to the viewer if the image encourages the eye to move around the image, rather than immediately fixating on a single place or no place in particular. Artists will often strive to avoid creating compositions that feel "static" or "flat" by incorporating movement into the image. In image A the 2 mountains are equally sized and positioned beside each other creating a very static and uninteresting image. In image B the mountains are differently sized and one is placed closer to the horizon, guiding the eye to move from one mountain to the other creating a more interesting and pleasing image. This also feels more natural because in nature objects are rarely the same size and evenly spaced.
These principles can be means of a good composition yet they cannot be applied separately but should act together to form a good composition.
These paintings all show the same subject, the Raising of Lazarus, and essentially the same figures, but have very different compositions: