According to Arguing Art, balance is the easiest art principle to understand. It consists of work being even throughout the piece in terms of color and forms. If such elements aren't even throughout the piece, the piece can feel heavy and out of order. Harmony is how the colors and shapes flow throughout a piece of art. When a piece has harmony, it is less-complicated and easy for the eye to take in.
Variety is the opposite of harmony and consists of differences in shapes, sizes, textures and colors. For example, Arguing Art uses a circle as an example. A painting of the exact same circle has no variety. But a painting consisting of different circles, does. Movement is how the artist directs a person throughout the workpiece. Arguing Art uses eyelines as an example of movement. Often, in an art piece, if people are portrayed as looking at something, the viewer will tend to look directly at what it is they're looking at.
Rhythm is how an artist portrays a pattern throughout a piece. For example, this can be done through the repetition of lines and shapes. Proportion, according to Arguing Art, is simply the size of the piece itself and the elements within the piece. For example, artists can draw more attention to various parts of the piece by making them bigger than other elements in the piece. Proportion creates an emphasis on certain elements.
Do all aspects of the piece work together to create one, big, singular piece? According to Arguing Art, that's what artists should ask themselves to judge a piece on its unity. Unity consists of the piece flowing together. Emphasis is the eighth principle of art often included by artists. Essentially, it is the result of all the other art principles. It consists of the effect achieved when your eye is naturally drawn to one part of the art.