my shower is tiled and gives a very nice sound. the bathroom is connected to my music room so it is very easy to move a mic in there. i usually dont get too fancy. i just stand at one end of the shower and set the mic in there w/ me. i have done stuff where i sang into the corner and put the mic right behind me, also pointed at the corner.
i record alot of percussion in the shower too - shakers, maracas, kalmiba, claves and even melodica.
