Good friends don't put each other down or hurt each other's feelings. Good friends try to understand each other's feelings and moods. Good friends help each other solve problems. Good friends give each other compliments. Good friends can disagree without hurting each other.
Good friends are dependable.
Good friends respect each other. Good friends are trustworthy. Good friends give each other room to change. Good friends care about each other. That it is normal for friendships to change as we grow up.