Check the temp. You want warm water, not hot. "Water that is 1 or 2 degrees warmer than your body temperature relaxes your muscles," says Regine Berthelot, lead esthetician at Caudalie Vinothérapie Spa in New York City. Hot water strips skin's natural lipids, proteins, and oils, which compromises its protective barrier and makes skin feel dry, scaly, and itchy, says dermatologist Mona Gohara, M.D., an associate clinical professor at Yale School of Medicine.
Customize your brew. For dry or irritated skin, pour in a capful of bath oil. "Oils are hydrating, and those that contain rose, bergamot, or eucalyptus also decrease inflammation," Gohara says. Try Dr. Teal's Body and Bath Oil with Eucalyptus & Spearmint ($7; fragrancex.com). For breakout-prone skin or body aches, choose bath salts over an oil (some oils clog pores, which can lead to pimples). Your body absorbs the salt's trace minerals, such as magnesium and sulfate, which help soothe muscles, says Vanda Serrador, facialist and expert at The Body Shop.
Wear a mask. The 10 minutes you're reclining in a bath is the ideal time frame for a facial mask. "It takes that long for ingredients to permeate the skin," Gohara says. Resist doing anything else. "I don't recommend exfoliating or shaving in the bath, because you would then be soaking in what comes off," Gohara says. Plus, you can't get a close shave once skin has swelled. Instead, take these minutes to decompress; then splash off the mask, towel-dry, and apply moisturizer to lock in all that absorbed water.
Do a double scrub. Start with a technique called dry brushing. Before your shower, run a stiff-bristle brush (try the Round Body Brush, $12; thebodyshopusa.com) gently up your legs and arms, then in circular motions on your torso, Berthelot says. If you scratch your skin at all, use a softer brush and less pressure. Then step into the shower, wet skin, and apply a salt or sugar scrub all over your body. The double scrubbing action works wonders, but "limit it to once or twice a week max," Gohara says. "And when you get out of the shower, slather on a heavy body cream to protect the skin barrier."
Treat your hair. Before you shampoo, reach for a hair mask or hot-oil treatment. Distribute from roots to ends, then stay out of the stream for a few minutes. The steamy air lifts hair cuticles so ingredients penetrate each strand. Rinse, shampoo to remove the heavy oil, and finish with your regular conditioner.
It's time to give your basic masking routine a personalized upgrade. Multimasking—applying multiple masks simultaneously—allows you to target specific treatments only where you need them. For example, a hydrating cream mask goes on any red, irritated areas, while a clay mask absorbs oil in slick spots like the T-zone or chin area. To incorporate a sheet mask in the mix, simply tear off a portion of one of these single-use paper or cotton cloths, and place it where you need it. Ten minutes later, rinse and glow.