There is nothing greater than self-giving love. Therefore, the best thing you can do in your life is to learn self-giving love. Where do you learn it? From God, who is the essence of love (1 John 4:16). Every relationship in your life is a training ground for you to learn God's way of self-giving love.
A good definition of love is "The commitment of my will to your needs and best interests, regardless of the cost."