Delight in details. That’s our guest room mantra. The late Franco Sersale, who for decades was Le Sirenuse’s arbiter of taste and doyen of décor, liked to reserve some of the best of the antique furnishings and artworks he collected for the rooms, where perhaps only a couple of hundred guests each year would see them. Like him, we obsess about the artisanal floor tiles, the bedlinen and furnishing fabrics, even that molto molto dolce vita straw beach bag. “Rooms are where guests spend most of th