With a limited budget I’d focus on cheapish light tile for floor.

...
Then you can diy-
Wallpaper
Beadboard
Art

And then add decorative towels.
Plants
Candles
Small frames

Are you changing the faucet to the gold finish? How bold are you willing to go with wallcovering

Yes, I'd love to go bold. Do you have a suggestion?

Yes, will be updating the faucet to gold as well.

Is your view that it's organic-transitional / textured floor, etc.? Your curtain seems a blend?

With nice vanity lighting a 'warm', it would seem the same finish should continue up and down the vertical.

Wallpaper - not Granny’s favorite decor anymore. I’m doing wallpaper in 2 soon to be updated bathrooms. Small bath with grey paper and fine gold twists (I have champagne bronze fixture) and in my bath a bold teal and grey looking like modern waves. The wallpaper will add some color and drama to an ordinary space. Etsy has some interesting selections which surprised me.

The sink has a nice oval going - how about this similarly fluid shapely faucet ?

https://www.lowes.com/pd/Delta-Linden-Champagne-Bronze-2-handle-4-in-Centerset-WaterSense-Bathroom-Sink-Faucet-with-Drain/50090926?cm_mmc=shp--c--prd--kab--bing--pla--225--50090926--0&kpid&placeholder=null&gclid=f0016f5bb9fb1e0057e20e65c3cf54ae&gclsrc=3p.ds&ds_rl=1286981&msclkid=f0016f5bb9fb1e0057e20e65c3cf54ae&utm_source=bing&utm_medium=cpc&utm_campaign=PLA_KAB_225_Faucets-Showerheads-And-Bath-Decor&utm_term=4585444528309332&utm_content=KAB_Sos-Faucets_PLA

https://www.lowes.com/pd/Delta-Single-Handle-Centerset-Bathroom-Faucet/5001895853

With solid rug - this could work with countertop, with curtain -- organic. I wipe canvas ok in bathroom.. what little drops get on it.

Platinum Shadow I by Cheryl Martin Canvas Print · More Info

It could be that with unframed mirror next to it, this frame could add contrast, well enough.

Pink and Red Floral Botanicals 16x20 Walnut Floating Framed Canvas · More Info

With pattern of nearby curtain anyway, the little wall space above toilet could be empty. Over towel bar [?] on back wall, could place larger art. Towels whatever color you prefer.

Fine Art Photograph, Maple In Style 1, Hand-Stretched Canvas · More Info

'Japanese' Canvas Art by Philippe Sainte-Laudy · More Info

Red Gardenia Close Up Flower 16x20 Canvas Wall Art · More Info

I'm done 'clipping photos' - but I like this - what colors do you use in the rest of your house??

Doris Reindl 'Krokus' Canvas Art, 22x32 · More Info

Thibaut Daintree

We might suggest adding an accent color and a you could always paint or use wallpaper. Here is a bathroom designs of ours with a darker vanity:

Contemporary Spa Inspired Bath · More Info