Think before you type, then ponder before you post.
We must we willing to take time when we respond online. Vet sources, think through issues, consult others, be careful with wording. Consider the tone and go overboard to communicate your true meaning. Truthfully think about speaking to the person privately (PM/DM or face-to-face if possible). But once you’ve created your masterpiece of a post, wait. Like, hours. It might even take an extra day or two. Let the emotion fade before responding, especially to an issue that has you riled up. You may find that after some time away you really don’t care enough to send that post.