1. Make fast waves
Hair truth: The less washing and styling you can get away with, the healthier your hair will be. So spin your day-old blow-dry into tousled waves: First, spritz your roots with dry shampoo to nix oil and thicken hair. We like L'Oréal Professionnel Fresh Dust, $19. Then wrap big sections around a large curling iron, "twirling the front sections away from your face," says hairstylist Ted Gibson, who works with Jessica Chastain. To finish, use your fingers to shake it all up.
2. Twist it up
On day two, try a French twist--unwashed hair makes it easy and seductive. "Its coarse texture helps the style stay put and look more casual," Gibson says. Back-comb your crown a few times to create volume, then gather your hair at the nape of your neck, slightly to one side. "Holding the ends, twirl your hair and keep twirling as you pull it up and against your head," Gibson says. Stick a few bobby pins horizontally into the roll's underside, and tuck the ends into the top. Take that, Audrey Hepburn!
3. Do a messy knot
By the third post-shampoo day, hair can get a little disheveled. The insta-fix: Roll with it--literally!--and do a loose bun. "It's great for the office because it still looks polished," says hairstylist Jet Rhys of the Jet Rhys Salons in San Diego. Begin by making a low, loose ponytail, letting any stray pieces fall where they may (they'll soften the look even more). Then, "wrap the tail around itself like a cinnamon bun," says Rhys. Pin the knot in place, tuck the wisps behind your ears, and go.
4. Braid it (just barely)
Yes, you can eke another day out of your 'do with a relaxed, weekend-perfect braid. "It's the low-key way to look pulled-together," says Rhys. The sexiest strategy: Start the braid at the nape of your neck (or, for you plaiting pros, do it French-style, starting a few inches higher), guiding it over one shoulder; wrap an elastic around the end. Tug the sides of the braid and around the top of your hair to loosen some strands. Now get yourself to brunch!
