I hang them on a hanger and if I have a dry cleaners bag around, I like to cover it! If the wreath will fit in a tub with the other seasonal decorations, I will put it in there and put it out in MY shed!
Everything is stored in plastic tubs and labeled. Then, stacked by holiday/season. Since moving, I am very blessed with space! I didn't have much space in my old house! (well...the attic was full with Christmas)