I am a huge procrastinator, but I don't believe that has anything to do with being "blocked." Writing is difficult, and it takes a tremendous amount of dedication and discipline. Sometimes, I want to avoid my manuscript because I know how much work needs to be done. The only way to overcome this is to sit down in front my computer and start writing (even if I know it will all be deleted later). Once I start, the ideas come. Sometimes, music and coffee help, too.