Some recent experiences have taught me some new lessons on the above subject. Have been trying for a while to sort of assimilate the information. Here are a few tips for avoiding fights and arguments:
1. Delay: This gives you time to think (of the effect of your words) before you speak. Use a niceness filter.
2. Never attack a weak-point : Every person has a shortcoming that he/she is aware of. Never hit the chink of their armour. For example never tease a short guy about his height or a dull girl about her intelligence.
3. Let go of your ego: If you stop caring about your own "importance" then you will hardly pay attention to any "affronts" to you - real or imagined. Then there will be no need to retaliate. This is actually the secret to never having quarrels/fights: Not minding.
1 is hard to do and requires a lot of practice.
2 requires that you know the person well. You might be unaware you are hitting on someone's weakness.
3 is hard even to accept; it is so contrary to what we hold on tightly to. But imbibing it will make you a much happier and friendlier person.