If someone looks good in yellow, make it a point to tell them that. I guarantee it will make their day.
If your friend's teenage soon went out of his way to exhibit quality human character, tell him just exactly how proud you are of him.
We are too easy to put each other down because acknowledging it some how makes us feel diminished in some way. I promise that it will in fact build you up when it is executed it in a genuine and purposeful way.