In the triumvirate of skin care (cleanser, toner, moisturizer), toner maintains its mystery more than any other product. Although most of us know when to apply it -- after cleansing, but before moisturizing -- what it does for your complexion is less obvious.

These skin refreshers, which often contain floral waters and herbal extracts, perform two important duties. When swiped across the skin, toner removes any dirt or residue left behind after cleansing. "I think of toner as the second part of the cleansing process," says Dr. Neal Schultz, a Manhattan-based cosmetic dermatologist and coauthor of "It's Not Just About Wrinkles." He adds that it's best to use a thin cotton pad rather than a cotton ball, which absorbs more of -- thereby wasting -- the product. Toner may also help restore skin's naturally acidic pH. Since many soaps and cleansers are alkaline, applying a slightly acidic solution like a toner can help keep skin balanced.

Essential to keeping skin clean, gentle toners with plant-based ingredients combat issues such as blemishes, fine lines, and redness. Toners with antioxidants, such as vitamin C, can help protect skin from wrinkle-causing free radicals.

Toners Versus Astringents
Two bottles contain the same ingredients, but one says "toner" and the other "astringent." What's the difference? In general, astringents are alcohol-based and better suited to oily, nonsensitive skin types. In contrast, toners are often alcohol-free and therefore suitable for dry, sensitive, and mature skin. However, don't let the label be your only guide: Check the ingredients to find out whether the product contains alcohol -- and avoid this if it doesn't suit your skin type. Plus, using toners with antioxidants, such as vitamin C, can help protect skin from wrinkle-causing free radicals.

Here are our favorites for each type of skin.
Wild Lettuce Toner by Burt's Bees
With lemon peel and lettuce extracts, this sweet-smelling toner refreshes your skin and senses.

Hydrating Mist by Juice Beauty
Aloe and oat extracts are among the complexion calmers in this toner. Glycerin and grape-seed oil help hydrate skin.

Refresher Course Exhilarating Face Tonic by Grassroots
Grapefruit and lime essences help balance and revive oily skin.

Tone Back the Clock by Nature's Gate
Cucumber and chamomile extracts calm irritated, sensitive skin.

Vitamin C Balancing Facial Toner by Avalon Organics
Wrinkle-fighting ingredients in this toner include vitamins C and E and green-tea extract.

Damask Rosewater Toning Facial Mist by Ren Skincare
This pure and simple mist made from organic Persian rose petals benefits mature skin types.

Text by Donna Garlough; photographs by Alexandra Rowley