What about 18 x 18's on the diagonal? That's what we did our floor and I love it!

This is right after installation, before the grout was washed off:

We used a similar size tile to yours, 12 x 18, laid horizontally with a 1/3 offset in our shower.

Thanks, treasure! Beautiful layout. What size is your bathroom? Did you do the 1/3 offset on the walls because of the large field tile size?

Would love to see any other floor patterns in 18 x 18, if any othershave pictures to share!

We have 19x19s in a diagonal pattern similar to treasure's above but without the small square decorative accent tiles. Placing the tiles on the diagonal give the illusion of the space being larger & more open than it actually is. With an 8x8 bath, over 1/2 the floor space will be filled with a tub and the vanity/toilet leaving only ~3.5 feet of open floor space. With that in mind, I would opt for a large tile that's not too busy preferably in a lighter color placed on the diagonal to help create the feeling of a larger space.

Thanks, onelady! Our overall bathroom dimensions are about 15 1/2' x 10' with about 6' x 6' of open floor space. I agree with mydreamhome about laying tiles on the diagonal. With the larger tiles you'll have less grout lines so that helps visually enlarge the space also.

We decided on a 1/3 offset for our shower tiles because I wanted to stagger the grout lines more and, because of the size of our tile (12 x 18), being a multiple of three, the math worked out great. I'm happy with the way our tilesetter laid it out so that it looks like one tile just continues around the corner to the next wall.

This is how it looks before grout, which will blend with the tile color.

I definitely struggled with the tile pattern decisions since I knew that they would really impact the way the room would look. Good luck!