Works must have "Qi Yun" a phrase lacking a true translated equivalent, sometimes referred to as breath of life. It seems as though a work must have perhaps what some english speakers may call "soul".

2.) Use of the brush - 
Brush stroke quality was judged heavily in Asian artworks as it was the same instrument used in other facets of life. Displaying proficiency and mastery of pressure, wetness, and thickness was very important. 

3.) Fidelity to the object in portraying forms - 
Works should include some amount of naturalism, reflecting the world from which they were inspired. 

4.) Conformity of kind in applying colors - 
Even black is considered a color and its range of darkness used to imply shading in the natural world. If colors are added other than black they should be reflective of the true colors of the subject. 

5.) Proper planning - 
The layout of the work should be premeditated and planned before touching paint to paper. 

6.) Transmission of past experience - 
This is the canon I struggled most to understand. It seems like ones art should honor those who have come before and should reflect past struggles or events. Perhaps in an effort to keep record and follow the teachings or warnings of your ancestors.