Paul Graham has a great piece on how to disagree with people in the best possible way.
He provides a hierarchy, with 7 being best:
Name-calling
Ad hominem
Responding to tone
Contradiction
Counterargument
Refutation
Refuting the central point
The TL;DR here is to evaluate any argument you’re having with someone, and see where each participant is in the hierarchy, and work to get to refuting the central point.