Simple common sense is the major factor in planning furniture for any room.
In a bedroom, for example, the largest piece of furniture, the bed, should be placed so that one doesn't have to walk around it to get into the room. In some bedrooms, there is only one wall where a bed may fit, but there are logical ways around this as well.
In one bedromm I floated the bed in an island-like arrangement, with a right angle headboard to give the bed a wall to rest against.
In another master bedroom, I placed the bed in a corner, diagonally, and used small rugs and sitting furniture in the same diagonal to make this unconventional arrangement work.
Living rooms, of course, are often the worst headaches. I've faced many rooms where the space was so broken up, or so narrow, or so wide, or so small that only the smallest scale furniture or the most bizarre arrangements could make the space work.
In one room of a Victorian house, the parlor was divided in half by the entrance door, and the fireplace was in the smallest part of the parlor, at right angles to the window. This window, a generous bay, fortunately solved this puzzling space problem. I built a soft window seat in the bay, taking the place of a conventional sofa, and arrangedthe other furniture - two small arm chairs, two ottomans and a coffee table - in front of the fire place, still leaving plenty of space to get into the room. The other half of the parlor became a large table for working or games, and a comfortable pair of swivel chairs. A television set and stereo equipment were easily installed on deeper shelves.
Modern houses often present arrangement problems as well. In a new house, the fireplace was at right angles to a window wall where a door opened out onto a flagstone terrace. It was an almost impossible space to use for seating because there were no walls relating to the chimney.
I chose a simple, tailored modular furniture system, on a modest scale. The basic module was only 32 inches in each direction, and combining these into a loose U-shaped arrangement made a comfortable seating area around *the fireplace. The furniture was arranged in an L first, one side with its back to the window but far enough removed from it to allow heat and cool air to circulate in winter and summer, the other half of the L facing the fireplace. Another pair of single modules, which could later become part of the same group in adifferent shaped room, were set far enough from the L shape to allow one to enter the seating group, or to pass in front of the fireplace to the sliding door and to the terrace outdoors.
Behind the group facing the fireplace, I used a slab-end Parsons table as an end to the seating, behind which is a wall storage system for books and stereo. This table not only makes a "wall" for the seating, it also became a handy work desk for the storage wall.
With the furniture placed in this system, a kind of informal barricade is established in this indeterminate and difficult space, keeping the seating area intact and separate for cozy evenings, yet allowing circulation.