I could see her smelling like a river, honestly. (It's a hard smell to describe, especially since I haven't been to the local-ish river in ages, but eh) Seems to go along better with her job/usual location.
For some reason, I always thought wet coins had a very distinct smell. Regardless, considering she spends her time around flowers and dead people, I don't think her scent would be based around the river. Genji would smell like a river though.
Sakuya probably smells like mothballs with a little bit of cleaning stuff thrown in. She spends almost all her time in SDM working for Remilia, I doubt she smells that fine.
Hina would probably smell like one of those extremely heavy forests. Unless curses have a smell, then she'd smell like that.
I believe Sanae, Yuyuko (does it count for a ghost?), Kaguya, and Keine among others would actually be perfumed. Marisa might be as well, depending on just how much use she gets out of those mushrooms. As for what perfumes fit for each person, well I'm no expert on lavish scents.
