Re: Is this tile layout the most efficient?
IMO forget about trying to save yourself a few cuts here and there when laying up a floor on the diagonal. When tiling small spaces or hallways the finish look always out weighs the effort it took to make it.
You’re asking us about layout, well I have to ask you, are you installing a vanity that goes right to the floor, a free standing vanity or a pedestal sink? The reason why I ask is because that determines how much floor will be exposed along the left side wall and that will/ should dictate the tile layout pattern. The pattern of tile layout should not be determined as an empty room, but more as a completed room.
If you do a full tile at the threshold (corner of the tile touches the threshold but not cut) then I think it would look bang on to offset your tile that 3/4" along the right hand wall (given your baseboard is 3/4"). Judging by your pics I think you’d have plenty of tile at the tub to look more then acceptable. But in saying that, I certainly wouldn’t be taking that approach if I were installing a pedestal sink and I would have to seriously think things through if I were installing a free standing vanity.