Freelance writing job listings are plenty across the web, many of them featured from contract sites who let you bid on piece work.
The competition is high on these types of sites and if you are not willing to work for little or nothing it can be hard to make a living with upfront payments to your work.
The best type of writing jobs are from private companies who pay on a consistent basis, also blogging for niche websites can be a good income for those who are knowledgeable on the subject.
Ghostwriting jobs are another area where you can write and then give up the writes to let someone else put their name on the content.
This works if you do not mind not getting credit for the work you have done.