Graduation Gift

I always cry at graduations and weddings. Not because I'm sad, but because I'm happy for the opportunities that lie ahead for those participating in the ceremony.
Just recently, my daughter came to me and asked, "If you had one piece of advice to give me, what would it be?" I told her that I would have numerous things to say, and she said, "No, just one." Without hesitation, I replied, "follow your passion."
For some reason I cannot get this question out of my mind, and I think this is because there was more I wanted to say. I would have told her to maintain self-respect and not to negotiate her integrity. I would have told her to listen to herself before she listens to anyone else. I would have told her to never ask for someone's permission to follow her dreams, and to always face her fears. I would have told her to love with all her heart, because the benefits would outweigh the pain of any suffering. I would have told her that there would be difficult times to endure, but to know she is never alone.
I then thought this would make a lovely graduation gift. A handwritten letter to the graduate sharing your own heartfelt advice. What one piece of advice would you give?
If I could only share one piece of advice, I'd have to make it a combination answer: Do not compromise your self-esteem and simply do what you love.