There are two steps in driving traffic to your hubs and they are both quite obvious:
1) Create Great Content. There is a ton of guides online on what "great content" exactly is, so I won't go into details. Just note, that after writing a useful article in an interesting way you need to pay attention to headings, pictures, formatting, etc. Ensure good readability and that a potential reader would enjoy reading your hub.
2) Content Distribution: The days when simply creating great content was enough to bring traffic are long gone. The competition is so fierce now that you have to promote your content if you want people to notice it. Again, there is a ton of online guides on content promotion. You can start from related FB groups, g+ comunities, subreddits, forums, blogs.
Simple as that BUT it requires hard work and lots of time.