Eau de parfum is the middle ground and the version most of us actually wear. It lasts longer than a toilette, carries the heart of the scent better, and usually needs only two or three sprays for a full day.

Chanel's Coco Mademoiselle is a reference point for a lot of people, orange and Turkish rose over patchouli, polished and a little sexy. Dior's J'adore is ylang ylang, Damascus rose and jasmine, a warm golden floral. Yves Saint Laurent's Black Opium is black coffee, white flowers and vanilla, a modern evening classic.

Viktor&Rolf's Flowerbomb is peony, rose and freesia, sweet but polished. Valentino's Donna Born in Roma pairs blackcurrant and jasmine with bourbon vanilla. Miu Miu's Miutine is wild strawberry, gardenia and brown sugar. Rare Beauty's Rare Eau de Parfum pairs vanilla and caramel, soft and warm. And Prada's Paradigme is bergamot and geranium over ambery woods, a men's scent that reads fresh and clean on anyone.

If you are only going to own one bottle, make it an eau de parfum. It is the most versatile of the three, strong enough for evening but not so heavy that you have to think about it at lunch. Spray it on your neck and wrists after moisturizing, and it will still be there when you get home. It is also the concentration most houses treat as the main version of a scent, so it is usually the one the perfumer fussed over most.

Parfum and extrait are the richest concentrations, and they are less about loudness than depth. Because there is more oil and less alcohol, the scent tends to sit closer to your skin, open more slowly and last longer, sometimes into the next morning on a sweater.

Kilian's Angels' Share Paradis is an extrait with raspberry liqueur, cognac and oakmoss, a richer take on the original. Merit's Retrospect L'Extrait is bergamot, jasmine and musk, clean and quietly long lasting, the rare extrait you can wear to work. Prada's Paradigme Le Parfum is ambery woods, vanilla and geranium, deeper than the eau de parfum.

Chloé's Le Nectar is a parfum intense with bergamot, orange blossom and tonka, warm and glowing. Jimmy Choo's I Want Choo Le Parfum is mandarin, jasmine and vanilla, and Burberry's Her Elixir de Parfum pairs strawberry and blackberry with jasmine, vanilla, amber and sandalwood.

Elixirs sit in the same rich territory, even if the name is a marketing word rather than a fixed strength. Azzaro's Forever Wanted Elixir is raspberry, cardamom and leather, and Armani's Acqua di Giò Elixir turns the fresh original into something woody and leathery with patchouli.

With any of these, dab or spray once on the pulse points and stop. One application of a parfum does the work of three sprays of a toilette, and it stays closer, so only the people you hug will really notice it.

Choose by season and setting, not by strength alone. In summer, or anywhere you sit close to other people, a toilette is kinder. For daily wear most of the year, an eau de parfum. For evenings, winter and special occasions, a parfum.

Remember that the same name can smell different across concentrations. Acqua di Giò and Paradigme each come in several versions here, and they are not simply stronger copies of one another. Perfumers often adjust the formula, so test each one on your skin before assuming you know it. If you love a scent but it fades by noon, try its eau de parfum before you give up on it. If you want to keep browsing, I also put together Night Parfum and Citrus Parfum.