Ooh-er, what a title. That'll take some living up to....
But luckily Alex Epstein has already written the post for me! ;)
There's a link to Paul Graham's website under "creative types" in the side bar. He's definitely worth checking out. A lot of his advice on business startup type things either applies directly to life as a self-employed screenwriter, or gives an excellent metaphor for the same.
I'm currently - and have been for some time - falling foul of his point 10. Avoid distractions.
"Nothing kills startups like distractions. The worst type are those that pay money: day jobs,..."
Best get back to the day job then ... *sigh*