Magic Forums

Does anybody know how to "properly" take down an altar. I'm a little confused since I should offer gifts to the god/goddess/diety/animal spirit etc...everything that goes onto the altar should belong to them, correct? Then how can I take it down, or take the objects off without offending any spirits or dieties?
Say I was to purchase a crystal statue of a dog to Hecate, how do I know what to do with it afterwords when I take down the altar? Would she not be upset that I still have the little crystal dog that is supposed to belong to her?
Or the same goes with food. If I was to offer cakes to Aphrodite, how do I know what to do with the food when I take the altar down? Do I burn the food? Or do I just throw it away?
I'm very confused could somebody offer me some advice?