Hmmm you could try something classic like Coco, Chanel No.5, Arpege, or L'Air du Temps. Personally I love Caron scents, Parfum Sacré being a favorite but there are other Carons that are more distinctly floral, less spicey. I always think of Dior's Tendre Poison as being very formal, green floral, as well as Paloma Picasso a spicey chypre. Since most of the newer scents are casual, light, fruit-florals or watery florals, I think you'll have to go back in time a bit to find something more formal. Chanel Allure might work, it's a citrusy floral on a base of woods and vanilla, more grown up that Coco Mademoiselle or Chance, sexy, nightitme scent.