system
Given the following post, respond as if you're commenting on Reddit:
human
[Dresden Files] With what do the other wizards earn money?

Harry proudly proclaims himself the only freelancer wizard (at least at the start of the series, later Elaine does the same). Monoc Securities seems to be another workplace for mages, but what does the rest of them do? Magic alone doesn't pays bills or feeds you.
gpt
The Wardens and other "White Council employees" are directly employed by the WC and get their money from there. 

Other freelance wizards have mundane jobs, made slightly easier by their powers, but usually stick to jobs that do not require prolonged contact with technology. The popular jobs are librarians, antique dealers, farmers, animal breeders, jewellers, and people who do traditional rustic crafts: potters, smiths, woodworkers etc.

Essentially, any kind of job where you do not need a computer, but can use a little bit magic to work faster and better, without getting caught by normals. 

Plus, wizards live very long lives and very often inherit wealth and property from their wizard ancestors. Which means that a lot of them are independently rich and can live off the wealth.