Measure your room space before you bring the furniture home. A sectional can be very large and take up a lot more space than you might intend.
Choose two pieces that have opposite arm rests, a beginning of the couch and an end. One arm rest will be for the right-hand side and the other for the left. These two pieces make one long couch set together or in an L shape.
Choose center pieces that will extend the sectional. This piece will have no arm rest on either side. Set up the sectional as one long couch or with the armed pieces in an L shape. The unarmed section is usually shorter and goes against the corner of the wall while one armed section continues in the same direction. The other armed section is perpendicular to the unarmed section.
Purchase smaller sections and V-shaped pieces to connect the sectional in a curve. V-shaped tables make nice connecting pieces and serve as end tables.