What's the key to a good parent-child relationship?

Let’s assume love is a given.

I believe the key is communication. I remember when I got divorced, my therapist stated that the greatest fear children had was losing touch with the parent they didn’t live with. Through the years, I’ve always tried to maintain active communication with my children wherever I might be. It has kept us close.

What do you think? What makes a good relationship between parent and child?