I'll be laying them "diagonally" so the grout lines are at 45 degree angles to the walls (regardless of *which* wall!).
As the house will effectively be one continuous stretch of tile, where you *start* plays a key role in what the final result is like!
We have a bedroom hallway down the center of the house that is a couple/three feet wide. I suspect having the tiles *centered* in that hallway will be the most visually appealing -- it would be too noticeable if they were offset in any way (small space means small discrepancies are very noticeable).
we have two other major "sight lines" perpendicular to this hallway. One is a "virtual hallway" (a view through several doorways/walkspaces -- even though there is a wall on only one side of this virtual space) of similar dimension. The other is a larger, "open" hallway (again, with only one wall but much wider space).
My thinking is to create a centerline down the bedroom hallway and another centerline for this "virtual hallway". Where they intersect, lay the "key" tile. So, eventually, a "row of diamonds" travels directly down the center of each of these "narrow" hallways/sightlines.
Everything else will just end up whereever the tiles end up laying (can't interrupt the pattern).
This makes the wide hallway a little less than ideal (the "diamonds" wouldn't be exactly centered owing to the dimensions of walls/rooms). But, it's a much wider space so hopefully not as noticeable "off center" as it would be in the narrower hallways.
It also makes the front entrance a bit wonky; the tiles again not lining up nicely in that space, centered on the doors, etc.
I've been playing with alternatives using a CAD model of the house floorplan (so, I can move the "grid" of tiles around and see what they will look like relative to the walls and openings) which is how I've discovered these compromises.
Is there some rule of thumb that governs how folks pick the point for the "first" tile (even if it is not laid first)? Or, do they just start anywhere and not worry about the outcome? (cover it with a throw rug!)