Almost every industry has networking sites that bring the community together. These sites are an amazing way to grow your brand and land new clients.
If you design, make sure you have a profile on Dribbble, Behance, Coroflot and/or Krop. Also join the discussion on Designer News.
If you’re a developer, be active on GitHub, Stack Overflow and Hacker News. If you focus on marketing and writing, dive into the conversations on Growth Hackers, Inboundand Reddit marketing.
I personally know several people who receive client inquiries from Dribbble and GrowthHackers, just for uploading work or engaging in the discussions.