what do you put to prevent them from sticking to the cardboard from the tier above? wax paper? powdered sugar? thanks!!

Powdered sugar and/or parchment paper work pretty good.

I cover them in celophane.

Press and Seal! Love it!

Oh yeah! That'd work great!!!

so the powedered sugar and or wax paper will prevent the fondant from peeling off with the tier above if its removed? cool

I find that making sure the fondant is quite set (at least a couple of hours) prior to stacking helps. I try not to put anything at all - in fact I put a bit of buttercream to help it adhere, since it helps anchor the next level.