you want it to look seamless, so follow the pattern.

a full tile to the half tile. Looks like you did the back wall first. Great, when you look down the side walls they shoull overlap so you don't see a joint.

/\ What Halllett said above, is the correct way to lay subway and most patterns.

Agreed. Half to half, full to full. What is your plan for finishing the niche edges ?

It looks great so far!! Very interesting tile color and opaqueness. Reminds me a bit of sea glass.

Yes to the advice already given so the tile looks like it bent around the corenr but that niche is going to give you some trouble to get trimmed now so that there is no change of it leaking .

Thank you for all the feedback. The plan is a mitered edge niche! @Patricia Colwell Consulting @BP DIYer