I agree with Duncan and only have one thing to add - imagine you are chatting to a friend. It should make it flow more easily - would you go completely analytical if a friend asked your opinion, or would you speak in easily-understandable language?

Hope that helps a little :)

The challenge is not to over think it. You want the content to capture who you are. Writing allows you to express your personality and thus knowing what your purpose is in writing the article, you are then able to align what you have written to that purpose.
Be yourself, don't compare what you are doing to someone else. All posts are opinion pieces - your opinion on the subject or product. That opinion will engage with others and cause them to express their views.

I hope that helps a bit.

Duncan