One of your regulars is in for a trim. You greet her at the front desk, walk her to your station, put on her cape and start your consultation, and poof!—little white flakes, EVERYWHERE. If you could use some help knowing what to do next, you’re not alone. So we asked two dandruff experts, Diane Cole Stevens, NIOXIN artist and artistic director of Cole Stevens Salon, and Christopher Langlois, scalp health specialist and owner of René Furterer Focus Salon Christopher Langlois Atelier in Pittsburgh, Penn., for their advice, as well as some common dandruff myths, so you…