Attached is the dimensioned floor plan (plaster dimensions!) for our bathroom. I am curious about your ideas. Unfortunately, I forgot to measure the position of the toilet (installed next to the washbasin). But it’s not that important anyway.
Funny, everyone has their own preferences. We have almost the same floor plan in the bathroom and I absolutely wanted the grout line in the shower to be centered, we have 60 cm tiles. Everything else then followed from this specification. We also had the back wall of the toilet cut so that it is centered, because I hate it when it is not symmetrical.
Therefore my tip: determine what is aesthetically most important to you and everything else will align with that.
For one person the shower is important like it is for me, for another it’s important that when they enter the room the room doesn’t start with a half tile, etc.
By the way, as has already been suggested here, we also used a different format 45x30 on the wall.
The tiler found it amusing but we discussed everything in detail beforehand how exactly it should be done and measured and sketched everything ourselves after I had learned from the mistakes of the ground floor bathroom.