Turn your tub into a tranquil oasis

A hot bath stimulates circulation and detoxifies, but it's also a mental vacation. When you remove yourself from technology and the outside world, it's a stress-reliever like no other, says Marcia Kilgore, spa expert and founder of the beauty brand Soap & Glory. Studies have shown that lavender scent can alleviate anxiety and help with sleep, so this soak is a great pick if you're stressed-out.SHOP NOW: Bath and Body Works Sleep Lavender Chamomile Aromatherapy Luxury Bath, $17

After a tough workout, pouring salt into your bath eases weary muscles. Bathing in salts helps replenish the minerals that are crucial for your skin's metabolism and also relieves stiffness, says Renée Rouleau, celebrity esthetician. Look for Epsom salt formulas rich in mineral-based ingredients, like magnesium, bromide or potassium. All three are known to calm the nervous system and reduce inflammation. SHOP NOW: By Nieves Rejuvenate & Relax Bath Salts, $18

Feeling under-the-weather and congested? Try soaking with a eucalyptus-based oil, says Rouleau. It clears congestion in your lungs and nose, she says. Plus, a tepid bath can bring down a fever and revive your spirits, especially if you've taken to your bed. Because the scent of this bath is potent, just pour in a single capful. After soaking for 15 to 20 minutes, you're sure to feel your clogged-up head and lungs clearing, so keep a box of tissues handy. SHOP NOW: Kneipp Eucalyptus Herbal Bath, $20

Bubbles are more than just decadent—they're also a guaranteed way to get super-clean. Suds are mild surfactants that rinse away dirt and residue, and don't sit on the skin like an oil or salt, says Ni'Kita Wilson, a cosmetic chemist for BeautySage.com. But the downside is that too many bubbles can dry out skin. Look for a moisturizing-based formula with skin-conditioning glycerin like Soap & Glory's. Post-tub, blot skin dry, and then apply lotion to lock in moisture. SHOP NOW: Soap & Glory Calm One, Calm All, $14

Cleopatra was the legendary for her milk baths, and to get smooth, supple-looking skin worthy of a queen, nothing beats a dairy dip. Milk is mega-moisturizing; the natural lactic acids gently exfoliate while the milk-fat proteins pump up hydration levels, says Wilson. But some formulas are simply oils that turn a bath milky white, and lack the active ingredients. To get the real deal, check that the label lists powdered milk as a top ingredient. SHOP NOW: Farmhouse Fresh Nectar Bath, $28

Essential oils benefit your skin and mind. Oil is great bath booster because it seals moisture under your skin, so you don't dehydrate and get prune-y. And the scent can add function like waking up your circulation or helping you to sleep, says Kilgore. Aromatherapy can be a powerful way to connect mind and body. Add a few drops after turning off the faucet (water pressure can break up the formula, making it less effective) and then breathe deeply. Or pop in an essential-oil-rich, fizzy sphere that releases scent slowly as you relax.SHOP NOW: Lush Cinders Bath Bomb, $5

What's a tub without a little soap-fueled rub-a-dub-dubbing? You're probably thinking bars have a bad rap—they're drying and slippery—but when you're soaking and cleansing, a bar trumps a gel, which can melt all-too-quickly in water. There are more natural, vegetable-based soaps and conditioning cleansers now—many bars are just as moisturizing as liquid soaps, says Ian Ginsberg, owner of C.O. Bigelow Apothecary. Look for natural formulas that produce a rich lather with ingredients like glycerin or shea butter.SHOP NOW: La Belle Vie Triple Milled Soap, $6