Clean the furniture to give it a fresh look. If your sofa, chair and loveseat have removable slipcovers, read the instructions on caring for the fabric. You may be able to wash and dry them at home or take them to a dry cleaner. Use an upholstery steam cleaner to clean any pieces of upholstery you can't remove.
Revive sagging seats and cushions. Flip sofa cushions and fluff up back pillows. If you can't get the level of support you want, consider having the cushions restuffed, which would be much less expensive than replacing the couch. If the seat of a piece of furniture sags, try a seat support. These folding pieces of stiff vinyl create an additional layer of support to help prop up a tired seat.
Check the supports if the seats still sag. Turn over the furniture and feel for bulging pieces of wood or springs. You can attempt to repair these issues by inserting blocks of wood between the frame and the sagging section or by twisting bent springs back into place with pliers. If you aren't comfortable with this kind of repair work or if the damage is significant, seek help from a repair service.
Liven up your furniture by adding new throws or throw pillows. Choose fabrics and textures that add interest and coordinate with the rest of your decor.
Change the look of the sofa with a sofa cover, which will protect the upholstery from further fading or staining as well as inspire a new look in the room. Choose sofa covers that are machine washable for more convenience.
Try renewing the furniture and the room by rearranging the setup. Move the couch to the other wall, create more than one seating area or mix in new accent pieces of furniture with your existing couch, chair or loveseat. Add some new or different lighting to change the feel of the room and the way your old furniture looks.