What is the best way to store breast milk?

Frozen.: In a separate freezer compartment, not a freezer "box" inside a refrigerator.

In the freezer: It is best early on (when your baby is only drinking 2 or 3 ounces of milk at a feeding) to store the milk in tightly ziplocked breast feeding bags in small amounts. Keep them in the very back of your freezer (not in the door area where the temperature fluctuates frequently) for up to 6 months. As your baby gets older, you can store larger amounts at a time.