Make Them Look Good
This post is rooted in my beliefs about being an actor, but I believe that there is going to be artistic crossover.
I realized that the worst mistakes I have made in art is when I made the choice to show off over entertain. I think that an artist needs to serve their audience before they can ask to affect them. Entertain them. Be of use to them. Then, make them think.
This made me think. With a title like "Mercenary Artist" it's easy to assume that your level of effort will vary depending on the pay, but I don't think that is a good approach.
Whether you are doing a student film for $50 or a Hallmark movie, you want to make the person glad that they hired you. You want to make their stuff look good, even if it isn't.
No one will see your meh performance and blame it on the script. If you are commissioned to do a painting and you half ass it because you don't like the rate; you just look like a mediocre painter.
If you don't think that they are offering you enough, turn the job down. If the script is so bad that you don't want the job, turn it down.
But once you put your hat in the ring YOUR reputation is on the line.
Make them look good, and you will look good.
Kick Ass out there,