The 8 Celeb Haircare Hacks That Can Turn Your Bad Hair Day Around

When he needs to send clients down the red carpet with awards ceremony-worthy volume, Scarlett follows this quick, three-spray routine: After blow-drying — but before using hot tools — he mists a dry shampoo and then uses a natural boar bristle brush to work it all through.

To give hair luster, oils are the go-to for Adir Abergel, who styles Reese Witherspoon, Kristen Stewart, and Rooney Mara. If you end up with greasy patches every time you use an oil, try Abergel's application technique: "Spread a dime size amount or less over your hands like you're putting on hand cream," he says. "Starting at the back of your head, apply with your fingers using light strokes from the mid-lengths to the ends and work forward toward your face." A few passes with a flat iron, which will smooth the hair's cuticles, can also get a gleam going, but Abergel advises keeping the temperature below 385 degrees to prevent damage. Finish with a shine spray.

"I call highlights chemical volumizer," says Hill. That's because the process expands the cuticle, making hair appear fuller. Hill's favorite trick is to paint highlights right on the roots (often as a "tone on tone," she says, without actually lightening the color) so hair instantly seems bigger and bouncier — even before you add styling products.

Like your complexion, your hair may need different products from day to day, depending on how dry, damaged, or flat it is. "In my shower, I have a regular shampoo, a cleansing conditioner, and five different hair masks," says stylist Bryce Scarlett, who works with Natalie Portman, Gigi Hadid, and Lily Aldridge. "Your shower should look like a medicine cabinet." If your hair is dry, swap your shampoo for a hydrating cleansing conditioner; if your hair is damaged and breaking, use a mask as your conditioner; and if strands are feeling thin, give them a boost with the lightweight gel mask.

To keep hair color appointments to a minimum (key for preventing damage), Hill has clients book regular shine-boosting glosses. "Whether you get your hair colored every four weeks or every 12 weeks, come in halfway through for a semi-permanent gloss to keep color from looking tired or the hue from going rogue," she suggests, adding that the process takes only 15 minutes. "When prepping clients for the red carpet, I have them come in for a gloss the night before." Can't make it to the salon?

"Chlorine and minerals in the water can deposit a green or muddy color," says Hill. "A filtration system is a must for my clients, or I have them use bottled water to wash." If you don't have the budget for a full-on filtration system or, um, gallons of Evian, a showerhead filter is easy to install and can significantly cut color-corrupting chemicals and minerals. The only catch: You have to replace the filter every six months.

You've heard it before, but I'll say it again: Regular cuts nip split ends in the bud. "The minute a split starts, it just keeps going and going," says Abergel. Plus, the eight-week mark is when a cut starts to lose its style. "Some areas of your hair grow faster than others and the layers start to change, making it a different cut altogether," he explains. Scarlett agrees: "Even if your hair is just long and simple, and you think you don't have 'a cut,' a trim takes off the dead ends and gives the hair more movement." If a celeb is prepping for a big event, Scarlett likes to give her a cut one week before, so she has time to adjust to the new look.

"When it comes to hair washing, less is more," says L'Oréal Paris colorist Kari Hill, who works with Michelle Williams, Zooey Deschanel, and Taylor Schilling. Water weakens strands and makes them more susceptible to breakage. Plus, it opens the cuticle, allowing dye molecules to escape and natural minerals in the water to penetrate (zapping vibrancy and shine). "If you're one of those people who can go three days without washing — you know who you are — your habit helps maintain color and the health of your hair," says Hill. If more than a day sounds like eternity, alternate between a shampoo and an all-in-one cleansing conditioner, which gently washes your scalp and strands without stripping away moisture.