From a little book on Chinese watercolors come these elements of the art.
chi - life spirit capturing the "inner truth of the subject."
ku - the structural strength of the brushwork; "simplicity, speed and spontaneity are the mark of a master's brush strokes."
the harmonious composition of the picture as a whole
mimic the masters - learn by copying the work of the masters.
These simple rules parallel the core of poetry. To be specific, all but the final one reflect an imagist style. Capturing chi, if such a thing is possible, also reproduces what little I know of the zen model, the art of the haiku. ku reproduces the vital core of an object, it works as the frame to allow the chi life. The holistic and harmonious image contains within itself various sub- principles. For example, pin chu or the host-guest principle, brings balance with a passive and an active element bound together in an image. Typical pin chu imagery in Chinese paintings might be a butterfly (active/host) and a flower (passive/guest). Such paired elements in a picture work to provide harmony, an interdependent, symbiotic whole. There is innate strength in such a relationship (ku).