These tips are for my own benefit, as well as for others.
(1) Try to avoid pre-judging the person who wrote something you feel driven to respond to. Ask yourself the question: Am I responding to the person, or the article?
(2) Make sure you read and understand the whole article, and the reason it was posted.
(3) Don’t post vitreol from an anonymous identity (this one is not for me).
(4) Try to express arguments in a conversational, rather than confrontational way. Put your ego aside.
(5) Respond (if at all) to apparently confrontational, illogical attacks with calm reasoning.
(6) Write your own pre-emptive articles expressing your thoughts on subjects you feel strongly about, rather than always just responding to others. Then, others might understand more of your reasoning if they research you.