Cotton is an essential material when it comes to building your bedding retreat. Not only is it comfortable and breathable, but it's machine-washable, so it's a breeze to quickly and easily refresh. Take this three-piece duvet set, for example, made from that must-have material. Including a duvet cover and two standard shams, each piece features a neutral solid hue and tassel trim for a fun touch. Best of all, this set is hypoallergenic.