Tip One: Don't follow the crowd
This means, try to find markets that no one else is servicing. Target manufacturers and other non-glamorous companies.
Don't worry if you know nothing about a particular industry. If you're a writer, you can research and write about anything as long as you're prepared to do some extra work, and aren’t scared of asking questions.
Tip Two: Nothing happens until you get in touch
We'll all got something to learn from the UCE (Unsolicited Commercial Email) pests. It's this: if you approach enough people, you get results. So keep sending out your proposals and letters of introduction. :-)
Apropos of which, please remember:
Please, please, please DO NOT send out your naked resume to people you think might give you creative work. If you do, I will be extremely disappointed in you. Send a letter introducing yourself, preferably containing a proposal. Here's an article that may help.
The important thing to remember is that when you approach people, put yourself in their shoes. Ask yourself what they need, that you could supply, then make them an offer they can’t refuse. :-)