What you've written is rubbish

That's what I tell myself twenty-four hours after thinking I've written something brilliant (I sometimes think in the third-person, this may or may not be a problem). It goes like this:

Immediately after writing:

This is the most brilliant and insightful thing that I've ever written.

Twenty-four hours later:

Meh

After coming back you can see these things for what they really are. The reader with fresh eyes can see the rubbish bits. Then it's time to rewrite it, or just to change most of the words. There's a difference. Rewriting involves dramatically deleting everything and starting again. The other is surgically removing every piece of wrong. Afterwards you're left with something new and shiny, and almost always better.

This is harder with things like blog posts, since it's out in the world straight away. Which is why I'll put up any old nonsense. What? I mean, um, finely crafted blog posts. Yes.