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.