No more grandma perfumes! Find out which fresh notes you're drawn to, how to keep your spritz subtle, and what will make your signature scent linger in a great way.

CorbisPerfume may be the most influential item in your beauty arsenal. Sure, blush and lipstick wake up your face, but the spritz you're spraying has an impact on your mind like no other cosmetic. "Fragrance can instantly change your mood," says Pamela Dalton, PhD, an olfactory research scientist at Monell Chemical Senses Center in Philadelphia. That's why it's so important to choose wisely and wear it in the lightest, healthiest way.

What's inside that bottle?
"There are no hard and fast rules when it comes to creating a perfume," says Carol Grant, a fragrance expert at Sensory Spectrum, a New Providence, New Jersey--based product testing firm. A fragrance can be made up of 250 ingredients in a lab, or you can whip up one at home with a few essential oils. But no matter the recipe, every ingredient used in a scent falls into one of three categories: plant substances from nature (everything from flowers to bark), animal products (such as wax from bees or natural musk, though this category is becoming less popular because some consider it unethical), and, the largest category, chemicals or synthetics (scents created in a lab).

"Natural ingredients like herbs and fruit are extracted, distilled, or pressed to yield aromatic oils, which often become the base for the perfume," explains Sue Phillips, founder of the New York City fragrance firm Scenterprises and creator of perfumes for Burberry and Trish McEvoy. Chemicals are used to create new aromas that aren't found in nature or to re-create rare ones, though most fragrances are a combination. Whether they're natural or synthetic, these scents are usually mixed with a combo of alcohol (to blend and stabilize scents) and water (to dilute), Grant says. The type of notes plus the ratio of perfume to alcohol and water dictates how concentrated a scent is—and how fragrant it is.

Hit the right note
Top notes, bottom notes... Pros rhapsodize about your spritz as though it were a song. What's that about? "Making a fragrance is like composing music. You use specific notes, or scents, to create the perfect melody or fragrance," says Pascal Gaurin, a senior perfumer at the New York City fragrance house IFF. "Fragrances are constructed to have a beginning, a middle, and an end. The top notes are the initial aromas that you experience when you first try a scent. Usually they're the lightest, and often they're citrus scents which don't last very long."

Next up? The middle notes, or heart of the fragrance, which can often include floral, spicy, or amber notes. And finally, the bottom notes, or what Phillips calls "the dry down." Although these richer, heavier scents (think woods, moss, or vanilla) are the most long-lasting, they typically don't fully develop until at least 30 minutes after you apply the fragrance. When perfumers blend three or four notes together, it's called an accord, says Gaurin, one of the noses behind such scents as Very Hollywood by Michael Kors and Tom Ford Black Violet. "Just the way great music has a memorable melody—like the opening chords of Beethoven's 'Symphony No. 5'—all successful fragrances have a successful accord," he says.

There are scores of great scents on store shelves and perfume counters (fragrance sales in the U.S. and Europe hit $12 billion last year), but is there a way to categorize all those bottles? Most experts classify fragrances into one of seven types (we've listed some of the most popular categories on pages 104 to 105), although "there is a lot of overlap, as most perfumes are complex blends that contain notes from more than one family," Grant says. The key: The most dominant notes in your fragrance determine their category.

The secret to keeping it subtle
The most sophisticated and fresh way to wear fragrance is low-key and light. You want to smell amazing in an understated way (not like you spritzed every last inch of yourself). To avoid perfume overload, limit your application to two pulse points. Or, for lighter fragrances like citrus-y ones, Phillips says, start by dabbing behind your knees and work your way up (wrists, behind the ears). And, remember, your sensitivity to scent increases throughout the day—so when shopping, save your swing by the perfume counter for the afternoon. The results will make you say, "Eau, yes!"