Back in HS/college, I sometimes had a problem with writing papers due to the fact that I just didn't know wtf to write. B/c of that I procrastinated, would get distracted with internet, tv, games, etc. But I realized that even if I dind't really know what to write, as long as I started writing SOMETHING (as sh!tty as it may have been initially), it got the ball rolling and I eventually would have better material written. From there it was easy to get most of the paper done and after that I could easily go back and edit the beginning parts.
Not sure if that made any sense but the bottom line is that if you just start writing sh!t (has to related somewhat to the topic) it just helps to get better writing later on.