Never tell God your plans
This may not be about writing specifically, but trust me when I say that every writer I know needs to bear this in mind:
Shouldn’t you announce your goals, so friends can support you?
Isn’t it good networking to tell people about your upcoming projects?
Doesn’t the “law of attraction” mean you should state your intention, and visualize the goal as already yours?
Tests done since 1933 show that people who talk about their intentions are less likely to make them happen.
Announcing your plans to others satisfies your self-identity just enough that you’re less motivated to do the hard work needed.
Actually, I’m inclined to think this is even more important for writers. You have stories you want to tell, right? Well, every single time you go telling your friends, “I’ve got this great idea for a novel/screenplay/webcomic — it’s about this guy who — ” . . . you’re telling the story. Don’t satisfy that story-telling urge in a way that leaves you with no actual story to show for it when all’s said and done. Keep your mouth shut and get back to the keyboard.
(And yeah, it does work with other projects, as well. I didn’t tell anyone when I started putting this blog together, and here we are.)