Writing a blog article is a unique form of writing. My 2 suggestions are:
1) Read/ study great writing. Leo from
Zen Habits is great. Also
Copyblogger has helped me a lot.
2) Practice practice practice. You WILL get better as you continue to write. Try different styles and formats for articles. You will soon notice which are most popular with readers. Personally, I know there is a HUGE difference in the quality of my articles from when I started the blog (4 months ago) to now.