Like perfume or eau de toilette, cologne is a fragrance designed to be worn on the skin. Spritz generously onto your wrists, neck and pulse points—your body heat will help to diffuse the scent as the day goes on. After applying your cologne, avoid rubbing or dabbing skin. This breaks down the fragrance, causing it to wear off more quickly. If you prefer placing fragrance on your wrists, be sure to reapply after frequent handwashing, as this tends to rinse off the scent. Replace fragrance after 12 months. Expired perfumes more than a year old lose the integrity of the original scent.