To be persuasive, you need to have a point of view, and then you need to make an argument that brings the audience around to that point of view. This is something that journalists do every day, and do very well. I strongly believe that the more you read of what professional journalists write, the better your writing will be.
A friend of mine, Simon Mossman, is a former journalist, and he has written a Slideshare presentation on a related topic.
These days Simon is a media and communication advisor and presentation skills coach, working with business owners and corporate leaders to address their business challenges through communication. If you like this presentation, check out Simon’s blogs at www.commseilleur.com and www.confidencetricks.com.au