I had a friend who wanted to become a professional photographer. He talked me into doing a critique of all his pictures -- thousands of them.

As usual, my conditions were that the judgment was absolute; I might not know why I rejected one, but I had awfully good taste as proved by being the buyer for and running the card and poster area of a large trade bookstore; therefore I knew salable when i saw it. From his thousands I assembled a portfolio with 20 pictures. When he used it to job-hunt he was shocked that people offered him money for copies of what he had.

I don't know art, but I know what sells.