Here are a few suggestions :
1. Write article with at least 700 words, more than 1000 words is even better. Anything below that will be under performing.
2. Make sure the article is of good quality. What I do is, "google" for the phrases I want to use to see if they are correctly used.
3. Work on your title (this is the most important), and your url should be almost the same, if not the same, as your title, containing the keywords you want google to aim.
4. Work on your first paragraph. (this is also very important), That's the first impression to attract people to read your article. And it automatically goes into your "summary" (unless you edit this).
5. You can analyze what I include in my hubs.... youtube, RSS, your hub links, amazon ad, good clear photo.
6. Learn from other hubbers with hubscore above 95...