Networking. Getting to know people. In this business, it's all about who you know, and more importantly, who knows you.
That being said, what kind of videography do you do? Weddings? There's likely a local wedding expo. Get involved with that. Put an ad in their magazine or on their website. Wedding gigs are probably one of the few areas where people will call you "from the book". So it's good to be listed as one of the local wedding service providers. Connect up with a few wedding planners. So now we're back to meeting people.
If you're looking for corporate or other freelance gigs, they hardly ever go spelunking in online lists for people they don't know. They call other people they've worked with over the years and ask for recommendations. Then they might check those folks out on an online list, like mandy.com, productionhub.com or linkedin.com. It's a good thing to have an online profile on all those sites.
Most of my long-term, stable clients either came with me when I left my staff job a over a decade ago, or were referred to me by my former co-workers or clients. Some of my best clients have come from one of the editors I used to assist "back in the day" who refers his clients to me when he's unavailable because he knows I won't go behind his back and pilfer said clients. Honestly and integrity are your best assets. He hands off clients that aren't a good match any longer. He hands off clients for various reasons.
I have never once, in all my time running my own business, ever gotten a job from someone calling me/emailing off the mandy.com or productionhub.com lists. I've gotten a handful or two of calls/emails, but nothing that ever led to an actual job. IMHO opinion, those listings are more for proving to the government and corporate HR departments that you are an independent business than anything else.
All my staff jobs (there were 3) came from being introduced to the manager that was hiring by someone. In the case of my very first job, it was my internship that a college professor set up for me that turned into a full-time temporary position when a woman at the company went on maternity leave. That job ended when she came back to work. The interview for the next job I got was acquired by my sister's fiance, who walked my resume into his manager's office and recommended he interview me. That wasn't my dream job, but when you're 22 and hungry, the midnight to noon shift cutting news looks like a great opportunity. And it was. Cutting news just isn't in my heart. So a year later, I went looking. My next interview was set up by an assistant editor at a post production house that I met at an ITVA meeting (now known as MCA-I: http://www.mca-i.org/). I went to that meeting on the recommendation of my video production mentor in high school, who joined me at the meeting and introduced me to that assistant editor. After chatting over a beer after the meeting, he decided that he thought I'd be a good fit with the small post facility. He walked my resume into his boss' office the next day and recommended an interview. When I walked in for the interview, the editor from the first place, the internship-turned-temp job, was in chatting with one of the sales reps. Turns out, that sales rep had the same job at the internship place that the woman who went on maternity leave had before she had it. That editor gave the thumbs-up about me to the sales rep, who shared with the boss. I was employee #11. I left that job to start my own business. The contacts I made at all three staff jobs now fuel my business.
So it's all about the relationships you build, really.
True story: I once got called by a producer to work on the trailers for his feature film because his neighbor is my husband's half-sister. I couldn't do that job because it started the two weeks we were finally taking for our honeymoon 6 years later. Which was sad. Not the honeymoon, but that I couldn't do the job. The honeymoon was great!
Get out, meet people.