I have been thinking recently about all the monsters whose profile pictures show them almost completely naked, just the sexy bits covered carefully by fur or something. While many might just prefer it that way, one of the books (maybe the first volume) has a whole section about how monsters will also try to find clothing that accentuates their appearance. I think there's a lot of potential for finding clothes that would suit certain monsters, maybe in cases that they're entering human settlements
(although maybe this potential can only be realized by someone with a bit of drawing talent. Or maybe if you wanted to try using it in your writing)
Monsters that I think would be fun to imagine some sort of outfit for:
Elementals (gnome, sylph, ignis and undine primarily)
Most plant types (if you had a potion to let your alraune become mobile)
Especially liliraune, cause they could get matching looks
Zombies, skeletons or mummies