I completed the right end wall all in one session today. It helped that it was just a big empty wall with no tricky cuts to figure out. I know that an experienced tiler would probably have been able to do all three walls in a single day, or two days at most, but I am not that tiler.

The red strip on the end is where the edge trim will go later. For the pattern, I decided to use full tiles plus a shorter piece on each row, alternating. It's not the same as the back wall pattern, but I think it looks OK. As it turns out, by coincidence, it's closer to the 33% that most guidance recommends. The full tiles on the right end wall are in the corner matching full tiles from the back wall.

In my tile pile for the Carrara tiles, I've got one full tile and a zillion little pieces of various sizes. I've also got about 40 pounds of a 50 pound sack of thinset left over.

Left to do:

• Deal with niche trim and the small niche sill.
• Clean up thinset from tiles and grout lines.
• Carve left and right edge trim to the tub contour.
• Grout
• Caulk.

Update: Because of poor craftsmanship on the back wall, I needed to slightly taper the right end wall. I didn't forget to do that, but I wasn't careful enough. A couple of tile rows at the top were further into that red area than I wanted them to be, by 1/8 to 1/4 inch. As a result, the 2x36 trim pieces didn't have enough room. I trimmed those tiles with my angle grinder diamond blade. That worked reasonably considering that that seam will get caulked. However, I couldn't get all the way to the ceiling with that round grinder blade, so there is an inch or so that still needs trimming. I'm going to try diamond blades for my oscillating multi-tool and my Dremel rotary tool. I don't yet have either of those blades.

Update: Well, what do I know? I figured the diamond blade for the multi-tool would be sort of OK for this and the diamond wheels for the Dremel would be worthless. Porcelain is tough stuff. It turned out to be almost the opposite. I ground away for quite a while with the multi-tool with only very slow progress. I think I might have been able to get all the way to the end, but it was going to take a while. On a sort of a break, I fired up the Dremel. On a smaller scale, it cut more or less like the diamond blade on my grinder. Even with the smaller radius, I couldn't get to the ceiling, and the body of the Dremel also got in the way. I was able to cut close enough that I could chip out the remaining pieces without seriously affecting the main part of the tile. The tiny diamond wheel also worked reasonably as a fine-grained grinder, which might come in handy as I sculpt the edge trim around the outside of the tub.

(The small brown triangle at the top is a sliver of porcelain that I chipped away after taking the photo.)