cgarr- now that's timing- I just installed the shelf/footrest last night! I will post a pic later today, after we grout the final walls! I bought all the stone pieces from a local shop. Incredibly reasonable, all the pieces were to my precise specification, with the edges I wanted. It was I think 7" 1/4 round, in the Crema Marfil 3/4" thick. Once again, I practically forget to put it in when we were tiling (I did that on the last bathroom). As you will see in the pic later, I notched out the tiles below, rather than above that I often see, so the look would be more fluid. Ultimately the piece will be secured by the tiles above and below when I put my foot on it. There is thinset behind it, but that is not where the piece really gets strength.

Sorry this is so long... but using *both* worked well in many ways for us; I "had" to explain it (1st post: can I put pix in these msgs?). We just did both bathrooms: a 3/4 bath & a full bath. We had our tile guy do the full bath (3-wall semi-enclosed tub w/ shower in tub enclosure) with 2 porcelain shelves in the front corner (at the shower wall). The smaller bathroom has a fully-tiled shower stall, the walls are in white straight-stacked subway tile; we had them build a seat at the back corner. The seat & floor are 1" rainforest green marble. It's my 16-yr-old daughter's shower (lots of STUFF), so we had him tile in *2* porcelain shelves (1 smaller, 1 a little larger 18" below it). On the side wall opp the shower wall: a framed-in niche (betw studs)-- the inner perimeter is lined w/ the marble. It looks awesome; plain white shower walls (straight-stacked subway tiles ) with that gorgeous green marble on the shower seat/ floor. No borders on the tile walls, but the inset, in that marble... very practical AND beautiful. We're not finished in there yet, but the hole where the medicine chest was (we moved the toilet & vanity) is now a niche over the toilet; it will have the marble trim... a piece of 3-d art will go there. The shower is approx 42"x42"; but it's way less crowded than my description sounds. Plus her various potions are neatly stashed, no bottles on the shower floor, no telescoping floor-ceiling racks, nothing hanging off the showerhead... (The shelves in both rooms are in the corners of the enclosures that are hidden, so it all worked very well. The tub surround was too open so we skipped the niche in there; it would've ruined the clean modernist lines of the tiled surround.

Yeah- the 3/8" are likely too thin, especially in the Crema Marfil... I went through this I think with Bill, as I planned my foot rest in our master shower. Also used 3/4" for the niche shelves. Crema Marfil in particular is easily cracked, as a mater of fact, when we were just cutting some pieces, the vibration would often break the tile (NOT where we were cutting!!). I used 3/4", even for just shampoo, etc.,. I prefer shampoo shelves opposite the shower head, for water, etc, but when I was going nuts tiling the hall bath (my first time) I tiled right over the place to put them... so 4 shelves turned into 2, and both under the shower head :-( Here is a link that might be useful: FYI my post

Thank you so much, @kmcg123 ! It looks awesome! Your herringbone tiles are 3x6in, right? We were going to try it with 4x8in herringbone and 4x16in subway brick to save a little money on the labor since our shower is 6x4ft. I was hoping since it's a larger space and the same ratio it would turn out ok! Fingers crossed, it will still look this good! At what height did you start your chair rail?