The best way to fight hair-dye stains is to prevent them from happening in the first place. Whether you're at the salon or in the comfort of your own bathroom, Valenti suggests prepping your skin by rubbing Vaseline Petroleum Jelly (£2) or your favourite conditioner around your hairline, the back of your neck, and on your ears to keep the dye off your skin.
"You don't need to put on much — it only needs to reach about half an inch from the hairline," she says. "It will act as a barrier and easily wipe off when you're done."