Unfortunately more than two layout lines won't help much because this pattern won't repeat in about fifteen feet I don't think.
One line paralleling the tub/shower wall and one more line perpendicular to that first line (near the back of the room) is all that is required. These two lines become your "base lines". Once those lines are laid down and verified you can start deep in the room abiding by both lines. As you progress across the room use a tape measure and a framing square to keep yourself on course. It's pretty easy. As you lay tile and progress remember to verify verify verify as you go.
Lay out some tiles dry to determine exactly where your base lines will best serve you before you mark them.