As a wanna-be minimalist I love an uncluttered room. But at the same time, I love a space filled with plants. The plants need to be the focus and there cannot be much, or any, other visual elements like art, furniture, or knick-knacks. A room with plants as a focus makes me feel out-doors.
I recently found and article touting the benefits of indoor plants:
https://greatergood.berkeley.edu/article/item/how_do_plants_make_your_home_happier
After reading the article I then searched for more info on this subject and found a ton of research on how indoor plants benefit mental well-being, reduce stress, enhance cognitive function, promote productivity, clean the air, increase positive feelings, and reduce feelings of fear and anger. Many of these articles suggest plants that promote the most positive benefits with the linked article referencing specific research on this subject.
There are so many articles on the benefits of indoor plants that go well beyond the one paragraph I wrote above so dig deeper if you like. Or you can just start to build your own personal jungle and reap the benefits.
Enjoy