Bring in natural light. "A frameless shower gives the illusion of openness. The less metal, the less you notice that a wall is dividing the space," says Alison Causer of Alison Causer Design. "In this master bath I really wanted the natural light to reach every corner of the room. Since we used dark, natural stone on all four walls, we really needed to keep the light moving around the room."She adds, "We also installed a skylight in the shower, which combined with the frameless shower door really helps convey an open feeling."