I have a theory that I'm confident applies to blogging and may apply to other things as well. It's my theory of 8. I think most people have about 8 good ideas rattling around in their head that they want to blog about. When the pressure in their head builds to the right level, they start a blog and pop out their first idea. It's pretty cool. They work their way through their 8 ideas and they get stuck. They've said everything they have to say.
They key is not number 9 it's number 12 or 16. The first 8 things are brilliant. After all, they've been rattling around in your head forever. You've had lots of time to develop, noodle and refine the ideas. Number 9 will be crappy. Number 10 won't be any better. Here's where you'll want to quit. You'll procrastinate on the next post. Number 11 will show up in your head a couple of weeks later. You'll rush to write it and then nothing. Slowly the blog dwindles to a slow death.
The only solution is to commit to writing on a schedule. Commit to one post a week, even if it's only an "I'm Still Here" post. The key is that you improve by doing. Let's face it, that principle applies to sports, surgery and a host of other pursuits. Why wouldn't it apply to writing too?