A scale plan of your space is a good place to start. Measure carefully as accurate dimensions are key and include features that are likely to affect the design, including windows, chimney breasts and doors.
If you are going to use tiles, choose non-porous bathroom tiles like ceramic or porcelain. Porous tiles, such as slate, marble and limestone need sealing every few months to prevent water damage. Only use floor tiles specifically for bathrooms on the floor so they aren’t