Minor tip that I got from my tutor when I did my dissertation. Make it so your presenting an argument, show both sides then make sure you draw conclusions for why you feel somthing is the way it is. Its easy to get dragged in to just discussing a topic without coming to any real point at the end.
On my animation course we had to do a major essay in the second year then the full on dissertation in the third year. My first essay barely scraped a pass, I spent a lot of time waffling on about the topic but by the end I had gone nowhere. My full dissertation was on the exact same subject, but I layed down the facts then drew my conclusions from them. The second essay got me a first .
So in conclusion, if your trying to put forward an argument its much easier to write.