Double duvet sets and covers complete the look of any bedroom. Luxurious silk feels cool against your skin, and you can snuggle into the warmth of brushed cotton in the winter. Duvets with smaller tog ratings suit the summer months, and the converse holds true.
As for design, contemporary floral prints and abstract designs look good in modern homes. Consider complete double duvet sets with a matching valance and pillowcases, or coordinate your own separates for a shabby chic effect.