Oda already told us what the Strawhats smell like:
-MONKEY D. LUFFY Smells like Meat
-RORONOA ZORO Smells like Steel
-NAMI Smells like Mikan and Money
-USOPP Smells like Gunpowder
-SANJ Smells like Cigarettes and Seafood
-NICO ROBIN Smells like Flowers
-FRANKY Smells like Cola
-BROOK Smells like Tea