A double band of dark pencil liner sandwiches a white marble mosaic border along the top of this shower. My eye goes straight to that detail so I barely notice that the rest of the field tile is large format (and therefore less expensive). This bathroom looks like a million bucks due to the creative use of line and the contrast of light and dark stone.
Tip: Mix sizes of the same field tile. Here the floor is a 4"x4", the bottom wall section is a 6"x12" and the upper wall field tile is a 3"x6", plus the mosaic border.