Now that you've learned the basics of putting a room together, the sky is the limit.  You can add your own variations to create a totally different room.  Here are some examples.

The music room is a series of mirrors.  Just as in the display room, the right wall is a mirror of the left wall, the ceiling is a copy of the floor flipped.  Add some texture, wood, wallpaper and a door and you have a cozy little room for playing the piano.  All it took was some lines, layers and imagination.  In this room, adding drop shadows gives the items in the room extra depth.  For perspective, remember to use the Deform Tool and the Ctrl key on the keyboard.

The windows follow the same principles as the directions for pictures on walls.  Measure the pixel area of where you want to put your window.  If you want something like the window in this round room, pick a scene and reduce it to a bit less than the total pixel area you want to cover.  Slice the image into parts and add the framing.  Now paste each as a separate layer.