Paint the room in bright, cool colors like light blue, light green or violet to help create the illusion of additional space. Avoid warm colors like red, orange and yellow that seem to approach from the walls rather than recede. Paint the ceiling and trim a lighter color than the walls to further the effect. Choose one focal point wall, and paint horizontal stripes to add width and depth.
Use your windows to create the illusion of width by hanging long, flowing curtains on a rod wider than your actual window span. Hang the curtain rod as close to the ceiling as possible, and install a bamboo shade in between the curtain rod and the actual top of the window to make the window appear higher than its true height. Alternatively, use white or light-colored sheer curtains to amplify the natural light flowing in.
Use lean, narrow furniture rather than wide, oversized pieces. Instead of long couches, break up seating with loveseats and chairs. Use multipurpose furniture to maximize your floor space. For example, use your ottoman as a coffee table, or place stools next to your sofa instead of end tables for occasional storage and additional seating. Mount your television rather than using a bulky entertainment center, and install wall shelves rather than taking up room with a free-standing bookcase. Position choice pieces of furniture diagonally to call attention to the depth and dimension of the space.
Group wall art horizontally rather than vertically. Streamline the art with simple frames, or mount the pieces with no frames at all. Keep the walls from feeling cluttered by leaving a well-defined space between groups of wall art.
Use mirrors strategically to reflect light and space. Create flow in the room by using furniture with glass and metal accents.
Stay away from direct overhead lighting. Instead, opt for wall sconces or tall, skinny floor lamps. If you hang lights from the ceiling, hang multiple fixtures around the room to create lighting zones.
Install large tile squares or wide plank wood boards on the floor. Alternatively, use light-colored area rugs with wide lines or large patterns.