For soothing you have a lot going on. I suggest the shower wall tile also for the floor. The pebble for the shower floor and back of niche. The countertop is a little busy and dark but it should kinda blend in a larger piece if you like it. Do a light grout throughout to match the larger shower and floor tile and skip the glass tiles all together. I recently did this project for a master renovation

I like everything you picked except the shower niche accent. I think it will very soon be outdated and honestly I have never been crazy about putting accent in a niche. It is usually filled with shampoo and conditioner bottles, you don't need to make it even busier. You may want to keep the same wall tiles for your niche and find 2 nice bottles that will look nice in the niche where you refill with shampoo and conditioner when needed. I like the counter, I don't think it is busy. You have plain floor and plain cabinet and everything is neutral. This will look good.

I agree the counter is too busy for “soothing”. I would do the pebble in the niche as well. It will be pretty.

I take my comment back. After looking at the bathroom S Reed designdid for her client, I like the pebbles but only if there are nice shampoo/conditioner bottles. I still like your counter top.

I think something like that could be nice too. It has more softness.