Usually, when I read my old blog posts, one thing I evidently observe is that my posts are affected by my temper at that time. I feel like I could have written them in another way (maybe due to my current temper). This leads to my next question: how do I ensure that my current mood is not changing the blog post's plot and reducing its quality?
The tried and true method of "Write an angry letter today but mail it tomorrow" is the best preventative measure. Trust me when I say this, there is something stress relieving about writing down everything causing you to rage against the target of your ire. As Anton Ego observed in the Pixar Film "Ratatouille":
We thrive on negative criticism, which is fun to write and to read. But the bitter truth we critics must face, is that in the grand scheme of things, the average piece of junk is probably more meaningful than our criticism designating it so.
Sometimes things are said in the heat of the moment that, when looked at with a calm tone, make you seem disproportionately the "wrong" person in the fight and yes, it's often something you type to intentionally twist the knife. It's also possible that the tone you convey in your mind isn't read (I've found so many people to be reasonable when I can talk over a voip then they are when I type at them in a chat).
The advice allows you to "get it out of your system" but prevents you from committing it until you cool off and come to your senses and see if it's worth it.
The simple answer is, "don't write angry."
For person to person interactions, there was a rule (old when I was young, in the 1960s) to "count to ten" before speaking. Some folks (possibly those who've seen a game of Hide and Seek and watched how fast a child can count) suggest doing so in a foreign language, or using some other method to slow down the count. The point, however, is to give yourself time to calm down and think about what you're about to do/say.
The same method can be applied to writing. If you have something you're writing about because you're angry, don't publish it immediately. Leave it sit for at least twenty-four hours, maybe even a week. Sure, it may lose timeliness, but if it does, you might well be better off not publishing it at all, rather than releasing words to the world that might cause hurt or even get you sued.
Read, re-read and re-read again if the primary matter is what you will intend to publish. Still again, have someone else do so for you for clarity.
If your message is on social media, then the best choice is to wait some period of time which seems to work for you. What you will state at a later date will likely be more measured and informative. You might embellish a thought or clarify a position simply by having more time to do so. Thoughts marinate, and the end result is better for it.