The important thing is to first wait for inspiration. You have to watch a lot of tv to "get ideas."
Also, when you sit down to write, you might notice that you are hungry, or thirsty. You might also notice that your books are in the wrong order. You really have to completely stop what you are writing and go and put the books in the write order and go get a snack.
Also, first log on, and browse the web for a while to get the juices flowing. Check out Facebook, HN, twitter, Google News, Tech Crunch. Just get the juices flowing.
If, by the end of the day, you haven't started writing, well, no problem, you can wait till the weekend.
If you have a trip planned, just do it the next weekend.
At parties, it is important to let people know you are a writer and are working on a project.<p>Those are the main ways people that I know write books.