I've been doing that more recently too. I say to myself do I really want to do this? Or why am I getting involved in this? Especially Twitter where you can't unselect yourself from a conversation.
My new mantra is the saying, "not my circus, not my monkeys".
I do this a lot, especially in Reddit. Trick I learned is I use my notepad now to type the reply, then wait for an hour and post it. This helped with few things:
1. Slowly improving in checking for typos
2. Reading something after a break helps framing my point better and helps remove the heated emotion from the text
3. I also don't save the comment, so I have to spend time searching for it. This further helps in filtering the topics that I don't care about
4. Using services while not logged in, basically be a lurker
Sometimes I do hit the Reply button though. I still have room for self-improvement. :-)