hi, i am about to tile my new bathroom. i have put a level line around the wall, about where i want to finish. i also have to go up the whole wall height where the shower will be. do i put the top tiles first and work my way down, cutting the last at the floor as req??? i have three fixed level areas. 1 the bath top edge.2 the top of the shower tray. 3 the top edge of the sink. starting at the bottom will involve juggling to get the finish top level correct all around. starting at the top means just cutting the last ones to get in at the top of shower ,top of bath and sink. what is situation normal, any advise welcome...