While I am by no means an expert, I think many would agree that writing titles containing a high search/low competition keyword is important. I have only been on HP for a couple of months now, but I at least a couple of my hubs are showing up on the first page of Google searches for those keywords.
Also, instead of writing your entire article in one capsule, consider using a new text capsule with good keyword titles for each section of your article. These are things I have found to be successful.
Other than good writing and title choice, advertising your hubs on social media can drive more traffic to your site. Some of the best I have used are twitter and facebook, however, I have been hearing a lot of rumblings about the effectiveness of Pintrest lately. maybe another Hubber could speak to that more directly.
Lastly, just write more articles! Some of your articles will be more successful than others. When one article attracts a good amount of traffic, try writing more articles along that same subject line. Hope that helps!