For short-term storage, you can simply roll up the pillow and pack it away in its stuff sack.
For longer-term storage, open the valve and lay the pillow flat – this will allow the internal moisture to dry out.
Correct storage of an Aeros Pillow is really important to prolonging its life. The majority of air-loss issues we see with Aeros Pillows are attributed to moisture from condensed breath remaining in the pillow when the pillow is packed away. The moisture can weaken the welds or the air proof barrier.