Mike Hinge was a wonderful artist I met early in my career. He gave me some good advice in the form of a lesson:
at the time he dealt mostly with publishers. Once you were hired to do a cover (for example) generally the editor would ask the artist for several mock-ups. Mike said he would make 5 or 6, then would look them over and decide which was the WORSE one. He would then discard that and NOT bring that one to show the editor.
He would only show the editor the best 4 or 5 .
Mike said that if he had brought the worse one THAT is the one the editor would want to use. Every Single Time.
Mike knew that businesspeople have no taste and you should never trust their judgment about such matters.
Artist should also insist on respect. Never do something for nothing. Hold that as a RULE. now, between you and me, we sometimes do certain projects for free, but the point is that it should be OUR choice and not dictated by the other person. Sometimes a project is worth it because it will get you cred, so doing it for free now means more money for future projects. But only YOU can know which project is
that kind of valuable. Others can't decide that.
The real trick is to discern the difference between people who only want to use you and people who Value your work. Avoid the first, be loyal to the second.