Textures on the floors can add an immediate design element. Perhaps a textured material or natural stone placed strategically in the center of the floor or as a perimeter band. Running your floor tile on a diagonal or diamond pattern has the effect of making your room look larger. However, expect to pay anywhere from $1.75 extra and more for a diamond pattern per square foot.
Design elements will add to cost as well. As much as $5.00 or more per square foot can be expected. Textures such as tumbled Marble would best be suited on walls. Round Riverbed Stones work well on shower home flooring and offer somewhat of a therapeutic value. Tumbled Marble or another color of Natural Stone used as a color band if incorporated correctly adds excitement and an "out of the ordinary" point of interest.
Colors. Always remember when using Natural Stone the installation generally costs more because tile setters have to craft, shape, grind, polish and form many pieces of the material. More often than not, there are no pre-formed corners and edges as there are with ceramic tile. And, the process takes a lot more time. You'll appreciate that more when shelling out $25 to $30 or more per square foot for the material alone.
Another point to remember is that almost any tile including Natural Stone can have a pattern! You really need to open up a few boxes to determine if you may run into an issue here.For instance, some time ago we installed a Walnut Travertine shower and walls. As I removed tile from the boxes and it was placed on the wall, we could clearly see we had reassembled the cut slab straight out of the box. This is unusual but it happens. In other cases the same grain or flow of colors in Natural Stone be it Granite, Marble, Sandstone, Travertine, and Gemstone may not look good. Dark tile areas might need to be distributed within lighter tiles so you don't wind up with too many dark or light tiles in one area.