So be courteous in all of your dealings with others. Be truthful, without giving offense. Remember the other person's name, and use it frequently. You like it when other people remember and use your name. So do the same to them.
Arguments are very negative.
They poison good human relations. You don't like it when someone argues with you. So don't argue with them. And if you see an argument coming, take the appropriate steps to neutralize the argument before it causes too much damage. Find areas of agreement.