Gretchen Tiernan and Megan Richardson, owners of Polish by Sand Spa in Manhattan Beach, Calif., wanted to make a posh first impression. The two decided upon an innovative design for their beachside salon that includes ombre spa chairs, iridescent soaking tubs, marble floors, and a sliding door to allow the sunshine and fresh air in. The salon not only has a calming effect, but it’s Instagram-ready (@thesandspa).