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