This is my mosaic bathroom ...It took me about five years all told, to  cover the entire bathroom with trees, birds, flowers and sky. Scroll to the bottom for some WIP pics and comments on progress - I've included the first idea sketch, too. That is as far as I plan before beginning and sketching the elements directly onto the wall. All the rest of the planning goes on inside my head.

I mosaiced directly on to the wall with a standard tile adhesive - I just prefer working directly onto my surface. The mosaic is done mainly with glass tiles and glass nuggets. Certain elements are standard tiles and glass. It is grouted in dark gray. And yes, grouting the ceiling is just as much fun as you'd expect it to be!