If he (or she) shares with you information about any important event in his life, take the opportunity to congratulate him, honor him and acknowledge him. You can give him a card. Or, take him to lunch. Or, even a simple handshake can go a long way.
Taking an interest in your employee goes a long way and it's one of the easiest, meaningful actions you can take.
If you manage a large team, you'll likely want to create a way to help you remember upcoming milestone events for each of your employees.