I love those long floorboards/wood-look tiles and they are the feature so you wouldn't want something too busy on the walls... personally I would go with a larger format say 300x600 rectified edge white tile with a matt finish for the Hamptons look... what's your vanity?... a timber one would tie in nicely with the floors and all the white... very Hamptons :)

also will give illusion of a bigger bathroom if you use bigger tiles ..I used small ones on one wall as feature wall and larger ones on other walls ..

I think she may have been referring to what is called a "French Pattern" which looks like a random mixture of square and rectangle tiles, often in travertine. However while it looks random it is actually carefully planned, and the tiles are made to a consistent thickness. It also depends on the type of tile that you are using. Many traditionally hand-made ceramic tiles have a natural variation, which adds to their appeal and visual interest. Other types of tiles, such as your porcelains are much squarer, flatter and almost identical. I would suggest that you go with your your choice of grid pattern, as laying a random pattern has too many risks (plus your tiler will hate you and charge lots extra). Be very careful about the selection of your tiles depending on your preference for a rustic more organic look, or a hard-edged architectural look. Make sure that the surface that you are tiling to has been properly prepared and is flat, smooth and true, as your tiler will not be able to correct imperfections if you have a bad wall. Best of luck, Dr Retro of Dr Retro House Calls

I have just laid grey floor tiles and white ( with a very subtle pattern) and I have used the same light grey grout for both. White grout is a nightmare to keep clean.