It might seem a bit retro—a flashback to when women would get their hair “done” at the local salon—but styling one’s hair doesn’t isn’t always a daily occurrence.   In the US, 80% of women wash their hair two to three days a week, or more often. However, when it comes to using hair-styling products or tools, one-third style their hair once a week or less often, according to The NPD Group.   “The Hair Consumer Untangled,” the market research firm’s new report, also reveals that products that ...