Suggestion: Perfumes
If the MC is wearing perfume it could give their attractiveness a small boost. Or if we make it even more detailed, there could be different types of perfumes, and NPCs might like or dislike it based on their preferences.
Viewing post in Course of Temptation comments
That's very doable, similar to how bad hygiene alters interaction effectiveness. Store favorite types in the person's data somewhere and apply bonuses when you match the type, I guess.
Although attractiveness as a stat doesn't really exist, it's all subjective to an NPC's personal turnons/turnoffs, and they can only have 2 of each (so it can go from -2 to 2 at the moment). It can definitely use some expansion later down the line, maybe even a separate system for tiny things like that where you can pick a lot of them, but they're not as strong.