I've seen minimalist furniture customized to an olive green color, and it looked absolutely fantastic! I've also seen mannequins with bath robes and face masks... I've also seen all of the marble pillars and statues used, and they look really good as well! Especially the Capricorn statue.
Add some greenery? Some green plants would look nice with the cool colors of the bathroom. I also second morifarty's idea of using statues/pillars. Some stuff from the Astrology DLC series (Aquarius Urn, Capricorn Statue, Pisces Lamp, etc.) would look nice. Maybe add some ambient lighting by customizing some lamps? I'm not sure what sort of look you're going for in the bathroom, but I have some Lotus Lamps that look nice in my bath/spa room.
The Bathtub and the Whirlpool Bath are also large items that can take up some space. You can also put a Bath Mat in front of the tub.
If you have the whirlpool bath and bathtub adding some things like the minimalist ottoman or some wooden stools might look cute next to it! Adding groups of plants in the corners looks nice also if you don't mind it looking like more of a spa thing.
Also adding some screens around the items can help fill up a lot of extra space!
Okay. My suggestions:
Replace the carpet with some kind of tile flooring, like ceramic tile or diner tile.
I don't know what kind of color scheme you're going for, but the cabana dresser with an aroma pot and a box of tissues might look good.
I'd also suggest the claw-foot tub, since a bathtub would be too large. Maybe with a violet screen in front of it, re-customized to white?
I'm not sure what kind of light fixture would look good in it. Maybe a paper wall lamp? A ventilation fan might be good just to have something up on the walls.
A washing machine might look good just to fill up some space.
I went with the striped set for my bathroom, because it has its own sink, and I was bored of the other sink I had been using. It works well in my "trying to be kind of realistically shabby" bathroom.