Read read read. Just like any creative writing teacher will tell their students to read as much fiction as possible, the same holds true in journalism. Read the news outlets you respect, the writing that thrills you, and even check out the drivel that tastes too gross to swallow...but give it a whirl anyhow to learn what NOT to do as a writer. Plus, reading a lot of diverse content may inspire you for story ideas you may not have thought of otherwise.
Craft a perfect pitch. It's an under-rated art form, but fine-tuning your story pitch is critical to becoming a successful 'lancer. It has to be sharp, concise, error-free and clearly illustrating why this publication would be interested in your story idea. Don't copy and paste pitches from one outlet to another; what works for Vice won't work for the Globe & Mail. Understand the publication's voice, tone and audience before hitting "Send."
Always Be Pitching. To riff off the classic Glengarry Glenn Ross monologue focused on "always be closing," I'd recommend having a pitch circulating in the ether...always. Meaning, if an editor rejects the idea, get one out there to another editor right away. At least one. That way, you are productive in working to keep the income flowing; and you're training your brain to Always Be Hustlin. Freelancing is built on self-motivation, which isn't easy to do when you begin your self-employment. Nurture it everyday by coming up with solid ideas, and finding the right home for your story.
Forget the content mills. From Elance to Upwork, these content mills are designed to give you a lot of work for very little money per post. In my opinion...no thanks. I'd rather work for respectable outlets at a higher rate, and I'd find a trade pub that pays well and has a strong relationship with freelancers. I'm fine with foregoing the mills, because one of the reasons why I got into journalism was to immerse myself in an interesting topic and learn everything about it. I'd recommend opting for the bigger magazines and online sites that interest you, which ask you to dig into the story and reveal its layers. The $ and respect you earn is well worth it.
Write great copy. Now that you have an assignment with your news network of choice, it's time to write. And you'll be graded by your editor on how well you a) follow the assignment letter b) file copy and c) write something they truly admire. It's not enough to file by deadline with something you worked on last minute. Give yourself enough lead time to research thoroughly, interview insightful experts and write sterling content you'd be proud to submit to the Pulitzer board. You're only as good as your last article, too; any glaring errors or holes in your copy could sink your reputation faster than you can say Jayson Blair.
Promote like a boss. Now that your article is finished and online, time to showcase it to the world. Of course, your news outlet will promo the article on their site and social feeds, but these days every journo has to be his own social media maven...and there's no shame in sharing your hard work with your fans on Facebook, Twitter, Instagram, etc. You never know if you'll get a gig from an editor or publisher who came across your post and is looking for a dependable writer in a certain field. Just don't overdo it; my rule is one promo post for every five posts on social, at the most.
Stay positive. It's easy to get dejected in freelance when the work isn't flowing as swiftly as you hoped. In the words of 2Pac, keep your head up. Rejection hurts but drowning in feelings of worthlessness hurts more. Recognize how the 'lancing life will give you peaks and valleys, and during the valleys you have to push yourself harder, pitch more, find other sources of revenue (copy-editing, content marketing, etc). You have chosen this life of ebbs and flows, so prepare yourself mentally for those slow weeks. I try to stay positive by writing poetry, and thus exercising my writing muscles still, and reading about writing, from fiction writers or other freelance writers.
Heck, you're already doing yourself a favour by reading these tips!
I'm happy to answer any questions you might have about freelancing, here or via Twitter @SilverbergDave.