Do you have any pictures you could posts? From your description I'd add as many live plants as possible, and some chunky candles - maybe in burgundy to pick up the color from your shower curtain. What color are your towels? Sounds like burgundy might be nice for those too. Maybe a new mirror over the sink (don't know what you have there now) - lots of inexpensive styles available. Do you have a spot to add a swing arm or acordian makeup mirror (mine is regular mirror on one side, magnifies on the other) - very practical and looks nice too. Good luck!

I am struggling with this in my own bathroom. we just did a mini redo and while I LOVE many many pictures/artwork in the rest of my house I am trying to keep the bathroom a bit more serene. but I see blank walls and I think what can I put there? or that XX that I have would look good there :) I think it looks lovely as is. If it were me, I would be tempted to remove the two pictures that you have on the tub wall and put something on either side of the window on the window only wall, but sometime it is hard to tell in a picture if that will work in real life.

Or you can use some baskets .

I've been thinking about it, too. Try finding towels and a curtain in the same or similar tone that you painted the walls. I think a monochromatic look is more soothing and spa-like. You already have white toilet, sink, and tub. You can add more white with a faux floral arrangement of white flowers. I like your idea for floating shelves where towel bar is (you could put extra towels on it, too). Then a piece of art with white matting and a dark chocolate brown frame. PS - just looked at your pictures again and I think the towels and decor you already have are fine - at least in the pictures, they appear to match the walls. All you need is a lighter shower curtain in same tone as walls and towels, and a more impactful piece of art, slightly larger. And try white buds/flowers idea. I still like your idea of shelves over the toilet.