After light research on fragranatica, this is what I've come up with.
SMELLY SMELLS
OPLA!Sanji, Zoro, Shanks, Mihawk, Buggy
SFW Headcanons
This was actually really fun thank you
Sanji
Fun fact about restaurant workers/chefs incoming!!
Especially in fine dining establishments, restaurant workers are typically either advised against or prohibited from wearing strong perfumes and colognes. It can interfere with both the kitchen staff's ability to cook and the guests' dining experience, since so much of taste comes from your sense of smell.
So fresh, light scents are what he leans toward.
Something along the line of grapefruit and negroli, just very light but still sophistocated.
Maybe with a little herbaceous hint of fresh parsley or basil, but very light. Definitely not oregano, oregano is for savages.
Overall light and flirty, because that's Sanji.
Zoro
Earthy, woody notes. Not just because he got lost in the woods—
No, but I'm getting cedar wood, sandalwood, maybe a hint of leather.
On the subtler side, I guess you could say more laid back scents.
Just very earthy, not too bold, more noticeable up close.
Shanks
Rum and questionable decisions.
No really though, definitely on the bolder side, there's nothing about him that isn’t bold.
I'm getting smokey, strong notes of leather and musk (particularly dragon's blood resin, one of my absolute favorite incense scents not self-projecting I swear), underlying notes of spice.
Just overall very bold, with the full intention of drawing you in for more.
Mihawk
Wine. He smells like wine. And murder.
Also on the bolder side for him, but not as bold. Bit more balanced, not quite as in-your-face.
High notes of spices like anise, cardamom, corriander seed, with lighter sour citrus notes such as bergamot to balance it out.
Just overall very refined and sophistocated, sort of casually seductive.
Buggy
He's a cucumber melon kinda girl.
Not even joking, straight Bath & Body Works.
Maybe even cotton candy, or he just grabs your perfume as a joke and ends up kinda digging it, who knows?
It's Buggy, though, so definitely on the flashy side.
Strong citrus and fruit notes in general. I really wasn't kidding about the possibility of cucumber, but maybe lemon zest, coconut, I'm getting very tropical vibes.
Maybe with fresh green/herb notes like bayleaf or tarragon.