Tiling Sequence: Ceiling, Walls, Floor - Where to Start?
I agree with Ahmad G Badr &amp; I hope this is a shower alcove. Sorry, I hate tile most anywhere. You want to minimize the view of corner seams or grout lines since they crack first &amp; are usually where cut tiles (sharp instead of pillowed or rounded edges) are placed.

Side walls should butt over the back wall &amp; floor &amp; ceiling should butt over all walls. This is also hugely beneficial if the shower pan ever needs to be replaced. The floor should always be done last to eliminate the possibility of damage.