How can I manage the baby blues?

Get out. Some baby blues are normal. Make sure you make time for yourself and your partner. Get out, have coffee with a friend, get some exercise, eat properly. If the blues get worse, consult with your physician and or see a therapist to talk about how you are feeling. Post-partum depression can be very serious and is more than just the blues.
Family and friends. True baby blues are transient and not severe. The best way to manage them are to surround yourself with your family and friends. Don't be alone. Company helps tremendously especially if they allow you to get some rest/sleep. Baby blues are made worse with sleep deprivation.