I would say, above everything else, if you are trying to rank well for a specific keyword, your website must almost "be that keyword" - make sure the content is really something new, best in your niche so that people will share it and link to it. Sure, social media, blogs etc. - but have you considered creating videos and posting them on youtube?
I would be careful with article submissions - Google is now very clear that all link building needs to be done with intent of getting real visits through the links you build - so your articles must be read by people and motivate them to click on your website. If you just post articles to article directories and nothing happens, Google might sooner or later consider them unnatural links.
Similar with directories - I would make sure you only submit to some decent local directories, or niche directories relevant to your business.
Hope these help...