Some thoughts on humility - the characteristic of godliness that I believe is at the heart of being able to avoid reviling:
1) It is interesting what happens when you stop and think about what you are about to say and ask, "Is this a humble way to say this? Am I seeing both sides? Do I understand what the other person really is saying - not just what I automatically assume s/he is saying? Am I reviling the person by saying it this way?"
2) Being poor in spirit does NOT mean never chastising someone for what they have said or done; it does NOT mean never correcting someone when they are wrong. However, it DOES mean not doing so in ALL cases when someone is wrong in what they say or do. It involves carefully weighing the options and offering a comment that is not personal, or emotional, or hyperbolic - that is not directed at a person but rather what that person said or did.
3) I like myself better when I am focusing consciously on humility.
I find it fascinating that the end of Matthew 5, where it admonishes us to not revile, comes full circle back to the beginning admontion to be poor in spirit. Truly, life and progression is one eternal round.