How to know if you should blog post (or not)
Write the post. Set it to publish on a future date. Read your post the next day, decide you shouldn't have written such bollocks, never publish it.
And that's how you can save face. When we are emotional about topics we sometimes regret what we say. By postponing your blog until you're in a rational mindset, you won't have words up on your blog that you might regret. Although at other times raw emotional posts make the best blogs, but that's people who don't care about embarrassment.
This is how I blog now. I used to post straight away and then regret my huge blabber mouth. Never again. Well, probably again, but I'll try not to.