Social Media is a good place to start. Include a short summary with a link to the article. Make sure the image that shows up from the article is eye-catching to increases engagement on Twitter or Facebook and consider using paid promotion methods. You can also search for threads on "content related" forums where the content of your article may add value to the questions asked in the thread. A lot also depends on what you wanting to achieve with your promotion, i.e. link building for SEO or traffic generation.