I agree with the advice to dry clean now rather than at the start of the season. I keep things in the dry cleaner's plastic bag. They fold sweaters over the middle with tissue, and I don't have a lot of humidity so the plastic bags are generally better than storing everything in a plastic storage bin. The storage bins are ok, I haven't noticed moths forming. But they can inspire a musty odor, so that everything needs to be washed, dry cleaned or at a minimum, aired out when removing after a period of storage. Even if the garments are put in the box perfectly cleaned.