Good question. If you are unhappy with your existing tiles, getting a stone slab is a great idea for a wall. There are fewer grout lines to contend with, thus giving the area a larger feel. Look for a slab that is 2cm thick (3/4 inch) as it is less heavy and takes up less wall space, thus making it easier for the fabricators to install. Interstone Marble and Granite is a great place to shop for slabs and tiles. The look of a whole slab delivers incomparable elegance to your bathroom. For your floor and wall tiles, chose a color that you see in the slab and keep the pattern subtle. This way, your accent wall takes center stage. It is also a good selling point down the road.