How do you avoid arrogance when replying to others without falling into false humility?

It's not easy to disagree without conflict. I try to admit I am not a Keeper of Truth and that I have often been wrong. Avoiding name-calling and put-downs ("only a moron would think", or "when you grow up you'll understand" or "you're old and senile, boomer") helps.

If a poster or responder speaks for themselves and not for all 'decent' humanity, it usually works. But not always.