Add an extendable sofa piece to your existing couch. The end piece looks like a chair or end to a sectional sofa. When you pull out the armrest, the piece extends, creating additional seating for two or more people. Choose a color and pattern that match your existing sofa.
Extend your seating with armless chair pieces. These pieces match your couch, but because they lack arms, they fit between the end pieces of the couch. Arrange a few armless pieces in between your end pieces, and increase your amount of seating.
Mix and match armless pieces with other types of seating, such as an armchair or ottoman. The pieces add more interest to the couch, as well as more seating. Display a few non-matching pieces between the components of the sectional.
Arrange the pieces of the sectional sofa so that you have armless pieces on the corners. Place an end table at each corner. The tables hold drinks and other items, while making use of wasted space. If you need more seating when entertaining, cover the tables with extra pillows or cushions, and turn the tables into extra chairs.
Replace your coffee table with a low-slung ottoman. Pick an ottoman with a cushioned fabric top. When you need more seating, rearrange your sectional, and set the ottoman between the end pieces. You can also move the ottoman beside the couch or leave it as-is and let guests sit on it.