If you rotate your fragrances by season like you do your wardrobe, resist the urge to display all your bottles on your vanity year round. Exposure to light and heat can make your perfumes spoil more quickly. (You’ll know it’s time to get rid of them when they start to have an odd smell underneath the actual fragrance.)
Instead, when you’re done wearing on scent for the season or when you switch out your wardrobe, stash it in a shoe box in the back of your closet. Keeping it dark and cool will help it last the full two years that it should.