How does one determine criteria to evaluate a work of art?

You might look at the answer I just posted to a related question by Taneishaowens33.  

Another way to come at the question would be to think of evaluating a work of art the way you might evaluate a piece of writing.  I'll offer similar ideas for how you might evaluate an author's work or an artist's work.

What was the intent or aim of the author or artist?
Did the author or artist fulfill that intent well?
Did the author or artist have a unique idea to convey or an original approach to the subject?
Did the author or artist carry out the project with skill and mastery of the literary form or art form?
Does the work of the author or artist have a powerful effect on readers or viewers?

There are more questions like that which you could ask, but maybe those samples give you an idea.  Evaluating a work of art can be fitted into at least some sorts of criteria that will separate stronger works from less impressive ones.