I just put the lids on upside down on the pans, and then store them on top of each other. I reckon that would be fine, no?
I put bubble wrap in between my ones that I have to stack. I stack the 3 skillets with bubble wrap in between and they have been fine for 9 years. Analon also do a cleaner for the outside to restore the outside finish if it gets dirty. It's available from debenhams as well and isn't expensive. I'm on the same pot from day one.
It's not to be used inside the pans though!