Trust Your Nose
A fragrance is not meant to announce a coming attraction or serve as a souvenir of your visit. In other words, it should arrive and leave when you do. Instead, think of a fragrance as an aural accent, like a paisley belt on a solid blue dress, a dash of color to brighten the overall impression of your presence.
How can you tell if you're achieving that balance? In general, if a scent is just noticeable to you, it's agreeable to others. Remember that fine perfumes are effusive; they travel well through air. Excessive application is not only wasteful, but can also make you unwelcome.
In some cases, your nose lets you down. You may have a sinus infection or age may have dulled your sense of smell. You can also become so accustomed to or fond of a fragrance that you don't notice when you're overdoing it. When in doubt, ask a friend (one whose nose you do trust) and err on the side of safety. Some people are sensitive to strong scents.