The most important thing is to choose the right tiles suitable for the particular surface. There are usually smaller tiles recommended to be installed on the walls and other surfaces and slightly larger ones to be installed on floors.
Also, you should always check that the tiles you purchase are of the same size as depending on the method they are produced, the variation in the size of the same kind of tiles may be significant.
Depending on whether you are planning to install the tiles yourself or you are planning to hire a specialist to do this you should think through which tools you will need. If you are planning on installing the tiles yourself, you will probably need the tile cutting machine, the right type of adhesive for the tiles and the right colour grout. The colour of the grout should match the shade of the tiles, as it will show between the tiles.
Also, when you are installing tiles to your bathroom, or shower, you should not forget to waterproof the surface of the floor and also the walls to avoid water seeping through the tiles and floor.
So make up your mind on the tiles – the shade, the size, the type of surface etc, select the right tools and materials necessary for installing and get to work!