1) The writing is not revising. When you are writing, just write! Do not stop. Go ahead. After review, Perfectionism is your worst enemy, especially in the early stages.
2) Start with what you already know. "The first projects come from the heart." In verbal conversation, effortlessly tell the other person what you already know. Then write the history. In fact, you may find it useful to record your own voice as you say is history so you can play again to write.
3) Write at least one page of your dissertation by day. But at least one page. And you don't have to be in order. Any page is fine.
4) Allow drafts. Quickly launch and iterate rapidly. The draft must be very hard. Don't worry about mistakes. But also turn around quickly the revisions.
5) Use a diagram. It helps to maintain a consistent flow throughout your dissertation. Try to construct a mental map - a "tree" of ideas with the idea of the base (root) of the central ideas and branches around the root, and so on.
6) "PowerPoint" his ideas. Then turn the slides in prose.
7) Seek feedback on a regular basis. Feedback helps to make the revisions turned quickly, too.
8) At first, ignore your audience. He writes for himself, first. Then, once you have written a lot, consider your audience, and revise. Write out, not inward.
9) Writing out of service is OK, maybe even preferable. I made the mistake of writing my first works of research with the purpose of introduction to the conclusion. However, research is always unpredictable and so amorphous that important intermediate sections would always change. Subsequently, would also make it the introduction and the conclusion. Now, start the intermediate sections first, then write the introduction, conclusion and final abstract.