I always lay them flat and wright dates and amount on them I found they store better and u can store way more that way I've stacked them in shoe boxes to organize them
I put mine on their side after they froze and had them in the door taking up both wracks and then had some on a shelf in the freezer too. It gets used so fast girl. You can never have enough! I almost ran out because my boss refused to let me have any more than a 10 minute break to pump once for 8 hours