Caring about someone who matters to you is is not judging him/her. Honest observation without feeling superior is the hallmark of true friendship.
Don't be afraid to speak out of an honest heart. Proverbs states that wounds from a friend are better than kisses from an enemy.
Don't withdraw from speaking the truth in love and compassion. If your friend/spouse/business associate receives it well, fantastic. Even if they don't, you have done the right thing!
Understand the difference between judging and observing honestly.