Here's a little something for some panel variety. When you have a window or a door in a scene, you can eliminate the panel borders, or even make the door or the window the panel itself. Here's an example from Will Eisner's Comics and Sequential Art.
Scott McCloud suggests in Making Comics that we're so used to the idea of "panel as window" that simply removing the panel borders makes us feel as if we've gone through the window and into the world it contains. In the above example, Eisner twists that idea a bit and shows us the borders of the door, but the borders take on the characteristics of the setting. The technique is different, but the effect is the same. It involves the reader.
