I love this list from Terry Small and have added my own.
1. Unstructured play.
2. Sunlight.
3. Nature.
4. Hugs.
5. Freedom to explore.
6. Play with parents.
7. Laughter.
8. Simplicity.
9. Belief in their goodness.
10. Daily rhythms and rituals.
11. A calm environment.
12. Compassion.
13. A shoulder to cry on.
14. Expressed gratitude for who they are.
15. Unconditional love from at least one person.