a few pics of thisbathroom will help us advvise
setting out can sometimes work easily and other times be a right pain to get right
sometimes you need to compromise some where and get a slither cut where you dont want it in order to make the rest work
it doesnt help when you have windows at different heights
it will also help if you let us know the size of tile
when im setting out I use a rod, which is a length of 2x1 marked with the width of the tiles plus joint, this helps me to visualise the cuts
as floors ,ceilings and walls are rarely perfect I never start with a full tile anywhere, I always try to get a cut at the floor and an equell cut at the ceiling, these cuts ideally should be at least a 3/4 cut, the same on edges to the walls but this gets complicated when windows are involved as the widows are focal points, so I try to equelise a cut either side of the widow and see how it works into the corners of the room
if you can get it even either side of the window but end up with unequell cuts to the wall ends try and get the narrow cut behind the door or somewhere else not so obvious, sometimes works other times you end up with unequel cuts and have to live with it
if I have a narrow cut (less than half a tile ) going into the corner I try to get a wder cut going out so it looks like the tile is following the corner as two narrow cuts or a narrow cut and a full tile dont look so good in a corner
take your time and make a rod
you can then play about with your setting out till you can get it best you can