I can add that for padding any hanger, thick old towels folded in 1/2 on the vertical grain to be double, and draped over the hanger like a shawl are terrific--cotton and well washed to remove the original chemicals. This is a good method for hanging leather and other garments that need a rounded shoulder area as well as torso support.
I also want to emphasize what was listed above about lining wood storage with foil. This is really why anything ceder is not desirable: it gasses off (that is where those tiny brown dots come from on old cotton garments). Keep all those wood fiber items away for the same reason (paper, wood hanger, wood trunks, wood shelving, cardboard boxes).
The gasses from plastic are less visable in damage. Plastic bags approved for food can store small items, however. Don't cover garments directly with plastic bags, you will sometimes notice the stickness of the product as it ages.
Lay horizontal any item whose weight will pull down its shoulders. If it must be hung, you can prepare a 'torso' type of hanger cover out of an old washed bed pad and fix the waistline of the hanging garment to that inner padding for support.
Always wash cotton garments before storing, if possible. Do not starch and press those antique muslin dresses and petticoats.
Moths: I have spoken with museums who also have this problem, and I hear that freezing the wool for a few days will kill the eggs, so now you know what to do with that old inefficient freezer out in the garage.
Finally the last 3 items for good long term storage: dark, dry, cool
(I know what you're thinking "yea, right", but at least you know what is ideal, and that will help you to provide your pieces the best situation possible<
Happy Collecting!
--Jennifer O