Read interior design magazines, looking for images of L-sectional chaises to inspire your own arrangement.
Draw a few floor plans of your room on graph paper; allocate one square on the paper to each square foot of space. Mark doors, windows and other immovable items, such as a fireplace and electrical outlets, which will influence your placement of the chaise.
Draw your chaise on the floor plans, positioning it in a different place on each one. Select a different focal point on each plan -- for example, the television, the fireplace and a large bay window. Position the back of the "L" directly opposite the focal point, with the leg of the "L" running perpendicular to it.
Leave room for people to walk around the chaise, so it does not interfere with the flow of traffic. Leave walkways at least 3 feet wide.
Position your chaise in the corner of a vast space, with both sections flush against a wall, if it is not the main seating area in the room. Place an occasional table at either end, with lamps on top, to create a suitable place for reading, sewing and other tasks.