"The Colour Wow Dream Coat Supernatural Spray ($28) is — no lie — a raincoat for your hair, shielding it from the moisture in the air so strands don't start to fuzz and poof the moment you walk outside. You use it like a heat-protecting spray: Spritz it from roots to ends when your hair is still damp, then blow-dry your hair. The heat activates the proprietary polymers in the formula to link together to form a waterproof shield over your hair (it doesn't work if you just spray it in and air dry). It's incredibly effective for my fine, highlighted hair, but I have beauty editor friends whose hair is naturally thicker and frizzier and it works for them, too." — Sophia Panych, content director, UK