One of the most useful advice I got (forgot the name and the link) is to never got further than two replies deep. Every time I broke that, in hindsight, it was dumb to do so.
"A rule that is almost always valid: never refute or answer a critic, no matter how preposterous the criticism may be. Do not let the critic teach you the cloth, as they say in bullfighting circles. Never charge the cloth, even if the critic resorts to actual misquotation."