“Hair static is caused by dryness,” says fashion hairstylist Jet Rhys. She recommends using L’Oreal Source de Richesse shampoo and conditioner ($23 and $33, lorealprofessionnel.com), which fight free radicals that cause static. Finish with a smoothing product: Davines Momo Cream ($21, davines.com)” adds moisture without weighing hair down,” Rhys says.