The topic: Choosing a topic is the first step and needs to be done carefully, once the topic gets approved, you do not want to be stuck with something that is difficult for you to work on. Make sure you consult the right people before you make up your mind.
The synopsis: The topic you choose, will need to be explained to your guide so he or she can decide whether it has an appeal. Keep the synopsis crisp and include the points that will show your prospective study in good light. Taking third party opinion in the process definitely helps if you want to get it right the first time.
The thesis: The thesis writing itself is a great task. Once all the approvals are in place, make sure to research about the topic as well as how the thesis is formatted and finish it off in style. When you know you are right, the result only becomes sweeter.
Finally have the book printed and bound and celebrate the success of your PhD thesis!