Try a 1/3 offset. Occasionally that works out better. Hardie backer is not waterproof. Be sure to cover the remaining exposed areas. It appears from your photo to be a lack of fasteners on the left wall. Studs can't be more than 16" o.c. Your professional did not leave you with a tile ready substrate.

I am in the middle of a remodel and the guys have started tiling the shower walls. This is a reasonably large shower about 70 inches long and 50 wide. We are using 12x24 inch ceramic tile laid with a 33% offset. They have completed tiling the 70" side wall and we have got into a discussion on how to continue the tiling on the two side walls. It has always been my understanding that the tiles would "fold" at the corners and the section of tile cut off from the 70" wall would continue at 90 degrees. They say that they prefer to "frame" the tiles on the 50" walls to get the best layout on the 50" wall and then let the corners end up as the pattern falls out. What I can see that I end up with a pice of tile 3" wide on one side of the corner and then have a 8" section continuing - this looks a bit odd to me but they say this is a layout they commonly use - my thought is maybe not with 12x24" tile and in an offset pattern. Most of the pictures I see on the internet show the "folded" tile look which is what I think i prefer but since the tile layout was started on the back wall may end up with some odd cuts at the ends. Just trying to get some feedback from the experts here as they will be coming back to start on the other walls first thing in the morning! Thanks

First, check the manufacturer's instructions for that line of tile. Large format tiles often have layout restrictions, ie, no 50% offset patterns allowed. Best bet? Graph paper. A scaled drawing. And bits of paper cut to scale to act as tiles. Mix and match until you see an economical layout that is aesthetically pleasing and also meets the offset restrictions for large format tile.

@tartanmeup - checking in to see what you decided re: corner shelves or one longer shelf. I want to add a shelf like you posted in my guest bathroom - on the wall across from the showerhead - out of the spray line (this is a tub/shower combo). If I was doing this in a larger walk-in shower, I would just have a false wall built on the lower part so it would be a ledge. However, it’s a tub/shower combo so that’s not happening. I decided against a niche (for a few different reasons) - decided to just add a few corner shelves since it’s a guest bathroom. HOWEVER, after I saw this, I’ve wanted a shelf: I was told to use Mapei Flexcolor CQ grout in order to avoid any inconsistent color issues. @palimpsest - is your shelf just held by the tiles above/below? Was it custom made for you? Last Q - how thick is it? @laurenn07 - your shower looks nice!