In the beginning was the word, that is the most important sentence ever written in a book. Words are what makes humans understand each other, with words everything becomes possible and without words nothing is possible, nothing can be created and nothing can exist.
You as a writer need to know which words to use in you article. First technique to improve is your search skills, you need to know how to search to understand the mindset of those who will search for the content your article contains. I already searched Google more than fifty thousand times, and you?
Second, you need to use a keyword tool every time you write a new article. You could be missing words you believe they do not have traffic, but numbers do not lie. Search on Google for keyword tool and sign up with Google Adwords if you have to in order to check the stats. Google is a friend showing this information.
Third, learn how to use Bold, Italic and Underline to make the article more interesting. It is hard to read an article full of plain text with absolutely no visual effect. Use it at least twice per article.
And finally never forget to make your article at least four hundred words long, it is the optimal size for internet articles, it is the best size for SEO and the best size to keep a reader engaged.