Trade secrets: At Comic Book Resources, Arthur Adams reveals DC Comics' cover-selection process:

"Usually I do about fifty different sketches for any one cover. I then send these sketches to Mr.'s Berganza and Palmer. They take the sketches to a huge staff of lawyers, scientists, and theologians. This committee then chooses the one that will be the most difficult for me to draw. Then , lately anyway (I think Eddie just can't stand to hear me cry anymore), Tom Palmer calls me to tell me which one they want. He tries to console me by saying the next one will be easier, but it never is."