Jar aromatics to keep them fresh but don't try to age them beyond a few years. I've done this by mistake and my results weren't bad, but in general, I understand aromatics don't improve much with age. The flavoring tends to fade, and as near as I can tell, the base tobaccos don't improve -- as Virginias might if unflavored for example. Sometimes bagged or tinned tobacco left around smokes pretty well, but not dependably. Sailors on the old square riggers used to keep their tobacco in cloth bags and used it over months or years on long voyages. Probably the berthing compartments in those old ships had some humidity to keep the tobacco moist. I suspect the tobacco was of some concern, since those guys didn't have many pleasures in life.