The qualities that make good composition seem to almost mirror the qualities that make good visual work more generally, which I pulled together a little while ago in poster form. The qualities most relevant to composition (with a little explanation) are the following:

1. Proportion – how do “things fit together and relate to each other in terms of size and scale; whether big or small, nearby or distant”? This is the most obvious quality of composition.
2. Emphasis/Focus – where is the viewer’s eye drawn? Creating contrast and playing with balance, rhythm or movement can make certain elements of a piece stand out and appear more important.
3. Balance & Unity – do all of the elements work together? Symmetrical compositions instil a sense of order and calm (think Wes Anderson) whereas asymmetrical ones create more dynamic and active pieces.
4. Rhythm & Movement – what is happening in the image and how does it draw your eye? Leading lines and underlying shapes/tones can direct the viewer to focus on certain elements of give a sense that a piece is going somewhere at a certain pace.
5. Pattern – do elements of the composition repeat? Using repetition can give clear structure or draw certain parts of an image together.
6. Contrast – how do elements of the piece appear different? Contrast may come in many forms including hue, tone or scale and can create dynamics within a piece.