Commandments of Friendship
Focus on what you can give; not only what you can get
Encourage your friend
Be willing to forgive
Do point out their shortcoming but gently (Honesty is the best policy, being honest will make relationship last)
Be reliable don't lie
Don't try to control your friends let them live their own lives
Be there for them in good and bad time
Graciously accept personality differences
Discuss debate but don't be disagreeable.
Be generous. Share time and resources.