Ok ...here goes ....hopefully the picture will work ! lol
The problem here is everything is well out of square and little can be done to correct it due to the room being so narrow in the first place, to make matters worse the plumber has fitted the toilet off square the opposite way from the wall ! (to be fair it would be hard for him to get right too !) ....so The only thing I can really do here is to get a square accross the room, so that I know the vertical lines on Wall A and B will oppose each other perfectly ......then I can correct the off square (on the toilet face steps C&D) as well as I can from both sides, to get them as square and equal as possible, so that it all lines through properly !
If I was to simply to take the tiles round the back wall (E) or the face of the toilet on the horizontal line ....then the vertical lines (of A&B) would differ by about 30mm ...resulting in the shelf tiles (C&D) being wedge shaped and looking like a total riot !!
I got it done eventually (as you can see) ....but it took a major amount of faffing around, as I've never come across this problem before ......so, I was just wondering if anyone knows a good technique to be able to transfer a vertical line to an opposing wall, when you have nothing to square off from ?
Actuallly ...looking at that picture it looks like it's in a ship at high sea or something ! lol ....that's just down to me taking the picture at quite a bad angle ! lol ....the room is just so small , everything is awkward !