Make sure the lid is on tight with spirits, and keep it away from the light. If the lid is loose, the alcohol may evaporate, and light can hasten the breakdown of the other elements that give flavor and character to the booze.
Wine is a different problem, as I can attest after having collected it for about 35 years. Although the alcohol in wine is unlikely to breakdown unless the cork is bad, the other elements do change over time, sometimes improving the wine initially but eventually causing it to go bad for one reason or another. All wine will eventually lose its appeal, tasting flat, fruitless, and even nasty.
White wine rarely improves with age, or improves only slightly. Top-end Chardonnay, for example, is usually best at 3 to 6 years and may keep for another decade or more, but most white wines are over the hill by the time they're 10 years old. Dessert wines, however, such as Sauternes (the real stuff, not what they sell on Skid Row), may improve for many years and can keep even longer than reds due to their high-sugar content.
Reds, especially very tannic wines such as Cabernet, often need 6 to 10 years to mellow out, but they MAY keep continue to improve for a decade beyond that and then keep for another decade or two, but only a rare few are good for much longer.
However, the idea that the older the wine, the better it is, is simply false. It depends on the type of wine, the wine itself (i.e., Two-Buck Up-Chuck ain't getting better without divine intervention), how it's stored, and other factors such as the quality of the cork (infection caused by bad corks is one reason that screw caps are making big inroads in the wine industry).
For long-term storage, meaning over a year, wine should be kept in the dark, at cool temperatures (ideally 55 to 60 degrees -- anything colder will pretty much stop the aging process, but there's no problem with leaving it in the refrigerator), in moderate humidity to protect the cork from drying out, and lying on its side to keep the cork wet so that it maintains the seal. Heat and light are wine's biggest enemies.
As a generally rule, if you don't have a proper storage place, you probably should drink any wine you buy within a couple of years of the date on which it was bottled.