Young hot and sexy has nothing to do with perfume in my opinion. It's all attitude. Feel it= be it.
Perhaps go to a nightclub and ask the kids with fake ID what their perfume. Or follow some hot young things as they go through Sephora sniffing......no offense to fans of these scents, but I'm guessing for laydees it will be the likes of Miss Dior Cherie, Light Blue, the reams of RALPH frags, Brittany Spears and any number of fruity candy confections that are out right now.
I like smelling like an old lady. *waits for flames*