The trick comes in when you have lots of breast milk and the bags don't stand up very well, even when you buy bags designed to do so. To save room in your freezer, lay the bags as flat as possible to save on space and stack vertically. Have one spot to put the newest milk and then throw it on the bottom of the pile once it has frozen.
When you freeze your breast milk in bags in this manner, they are very low profile. Many are no wider than your average CD case. This means more room for more milk and you don't have to deal with crumpled frozen clumps of breast milk!

