Where I get freelance tech writing/editing work.
This is a combination of hunting for work, talking to people you know and networking. It isn't all that different than hustling for RPG work. You just need to be prepared to look and act like the professional you are.
Freelancing gigs can be found with temp agencies (who specialize in technical writers) – though these are more like 3-6 month desk jobs that require you at the office 3-5 days a week. Not bad if you can get them. They can be found on Craigslist, or like websites, and can be job specific (edit a 1000 page manuscript or write a user guide for product X) or ongoing (provide daily, weekly, monthly copy for a website). Then there are freelancing gigs that are like gold – ongoing, regular job specific contracts with a big company who will give a 1-3 gigs a month as long as you keep producing quality work for them in a timely manner.
Job hunting is an active thing. You can't sit back and wait for people to come to you. You have to both look for the job and to advertise. Jobs can be closer to home than you know. I picked up one freelance contract from someone I game with because he discovered I'm a professional and he had a need.
Getting contacts and keeping them.
Like RPG work, you get turned down a lot because there isn't a demand for your skills – right now. Thus, for every rejection I get, I thank the person for taking the time to respond to me and ask them to keep my resume on file for future reference – politeness counts! So does professionalism. Then, I check back with them once a quarter so that my name is in the back of their minds.
The best way to keep a contact and to keep them contacting you with new freelancing gigs is to do quality work in a timely manner. Do not miss a deadline! This is paramount. If you are going to miss a deadline, let them know at least a week in advance and give them the date you will have it done. ("I'm sorry, I will not have Gig A done by the 25th due to being in the hospital with emergency surgery. However, I am out now and will have it done by the 31st.") Never, ever leave a client randomly hanging. And overabundance of information is better than not enough.
This is important: Do not take a contract that is beyond your ability to meet it – skill-wise or time-wise. Be honest, polite and firm. ("I'm sorry. I am unfamiliar with raw HTML code. While I am sure I could learn the skill, I do not believe that I could learn it and get this job done by the 15th.") Then, always give them an option to show you are flexible. ("However, if the due date could be extended to the 30th, I believe I could complete this job in the HTML style code that you desire.")
Finally, always have your professional quality business cards with you. You never know who you will run into at the coffee shop. I've met some of the most interesting people in random places and ended up with a contact or a contract or both, just because of a casual conversation and an exchange of business cards.
Managing "pays the bills" work along with the rest.
I take all my contracts based on what I have due when. And, really, the "pays the bills" work comes first. It's rather like eating broccoli before getting dessert. It's a fact and that's how you have to treat it. Now, if I have a huge RPG/fiction contract due in a short amount of time, I let my pays-the-bills editor know that things may not be done in an as speedy a time as he is used to. Most of the time, this is fine. He tells me upfront if something needs to have been done "yesterday" or not when he gives me a gig.
I usually manage my schedule two weeks out. What is due this week. What is due next week. This includes ALL of my writing – technical, fiction, RPG. I have it on a list in front of me so that I can switch between projects if my brain gets tired of one type of thought process. If things stack up, and they do sometimes, I allot hours per day per project.
Yes, this does mean that, sometimes, I'm still working at 10 and 11 o'clock at night. But, really, I think it is worth it.