It's the longest, most complex and probably the most important paper you've written since you first went to kindergarten. Now you are in sight of those wonderful three letters: Ph.D. All that's left is to write a dissertation.
Work with your advisor. Decide before you start how often they want to read your drafts, have meetings and critique your progress. Don't be shy about asking for the kind of feedback you want, whether you want frequent sessions or to be left alone.
Use your committee. While some students may not have any contact with them after the proposal defense until the final presentation, it's often helpful to engage them in your progress as you write your dissertation. They may even have suggestions if you hit a roadblock in your writing or research.
Understand that a dissertation is designed to support a theory or hypothesis. And the doctoral committee will be looking for your paper to be both original and substantive. The key is critical thinking, not data from experiments, so while facts are important, it is more crucial to show how you use those facts to support your thesis.
Write your dissertation well. Just because a paper is supposed to be long doesn't give you the excuse to ramble. Your grammar must be perfect, your sentences well constructed and terminology clear. And the whole paper needs to be logical.
Be flexible. You wouldn't be the first student to change dissertation topics after you've begun. Keep your advisor and the committee informed, but know that most people don't stick exactly to the schedule they've submitted. You may be able to drop certain portions of your original plan, add others and write a better dissertation because of it.
Plan your time. Set a schedule and stick to it. You know if you work best in the morning or pulling an all-nighter. Block out whatever time you have and need to work on your dissertation. Set goals such as writing X number of pages or working for a set period of time. Say no to others when they threaten to take you away from your work. Also, find a place where you can do your best work. Home may be too distracting, but you may find it more relaxing than the library.
Take care of yourself. A dissertation is a huge undertaking, and while it's easy to let it slide because of other pressing issues in your life, don't burn yourself out trying to do it all at once. Sleep, relaxation and a life are just as important as your Ph.D.
Stay away from jokes, puns or anything you might consider comic relief as you write your dissertation. Your doctoral committee may not find them so amusing.
Look into financial help that might give you more free time instead of working one or more jobs. Your school can help you find available resources. But resist goofing off instead of using that extra time to write your dissertation.
Check out dissertations written by others in your department. It may give you good ideas on how to structure your paper and on what the committee might like.
If you study at home, don't use a desk in your bedroom. Many experts say that can hurt your chances of a good night's sleep.