It seems it lacks light. I’d paint the walls (or at least half wall) in a bright color, and choose floral or stripped towels and rug with that color

Pick a pretty color you love for towels.

Add under sink organizers to maximize your storage under the vanity.

https://www.amazon.com/Pack-Trending-Stackable-Cabinet-Organizer/dp/B07XHVH2BN/ref=sr_1_4?dchild=1&keywords=under+vanity+storage+organizer&qid=1587074853&sr=8-4

Stack some canvases to the left of your sink.

https://www.etsy.com/listing/475005988/turquoise-gray-abstract-flower-art-wall?

For instance

Or you can paint the interior side of the door, or the cabinet above toilet

Idea of wall and combining textils

I think it looks stark because you don't have a mirror yet. You also have chosen a vanity light that has no color shape or texture to it. I wouldnt put a medicine cabinet in that isnt recessed. It will take up much needed visual space and look like an after thought. You can get medicine cabinets that are framed and recess into the wall so they looks like they are simply a mirror. Once your mirror is up if you still feel it is stark I would think about a textured wallpaper

Toronto Urban Loft · More Info

I also think your light selection could be better. I would think about bringing in some black metal finishes with your chrome.

For storage instead of doing a cabinet above the toilet I would do some shelves with basket storage to bring in texture .

designinteriorsouth's ideas · More Info

Have you considered more interesting light fixture?

Maybe a hanging plant, real or fake?

Thanks for thoughts everyone. Love all the ideas. Definitely agree with light fixture ( that’s what I get for being in a hurry ) .