Your exact course of action will probably depend on what you're doing now and where you want to go. The easiest way is to just stop doing anything for free. Barring that, you could let your customer service slide and explain that the cost of what you do is just too much to allow you to give unpaid work priority. Basically, act like an arrogant pro who expects his customers to take whatever they're given and like it, only more politely. Don't ask for money, but imply that it would help. Or you could just deliver substandard products and hope people stop coming back (probably not the best course of action if you want people to eventually pay).
Personally, I like doing this stuff for little or no money because it carries so little obligation. Then again, I deal with people who understand value and would gladly pay more than what I ask for products or will look elsewhere for services that I can't provide well enough/fast enough to meet a deadline. At this point, I'm thrilled to have moved from "work being published without my permission" (coughBostonGlobecough) to "work used with permission but without credit." Sure, it would be nice to have my name attached to all of the posters and pamphlets that will be all over Boston in a couple of weeks, but I think I can live without it (this time at least).
As for pay, well, nobody would be paying for what I do anyway, so it's a matter of doing it for free or not having it done. I think it's worthwhile to document the activities of a world-class fife and drum corps, so I do it. It gives me an excuse to spend a fortune on equipment and I get opportunities to learn how to use it all, sometimes in very challenging conditions. There's also the occasional international travel or premium access to special events.
Of course, I'm not a pro, so this might not be the sort of thing you're interested in. Still, working for free isn't without its benefits if you do it right.
