First is to have an underlayment to protect your subfloor from any water leaks that can make the wood swell, especially if it is made of plywood. The most standard underlayment are the backer board and cement board. And most experts prefer using a backer board as underlayment because it will make the surface level and protects the ceramic tiles from breaking for an extended period of time. Then put a seam tape and add a thin-set mortar to cover the gaps between the wallboard and the backer board. After that, you need to apply a high standard water resistant exterior primer to the areas where you will install the tiles. Then you need to plan out where to put the first tile and measure it carefully. You can set marks as a guide to avoiding unwanted results. Then mix the other thin-set consistently to be used as an adhesive for the tile. Then wipe some wet sponge to the underlayment before installing the tile to avoid cracks and brittle set. These are just an overview of what is under a tile.

Doing everything requires time and patience because even experts commit some mistakes in installing it. So, if you are having a hard time doing it, your tile installers are always here to help you!