Sew a patch on the area that is ripped or torn to keep more stuffing from falling out. Don't worry about how it looks because you'll cover it up.
Place some coordinating throw pillows on the couch to decorate and disguise the patched area. If you're worried about pillows shifting, attach some self-adhesive Velcro to the side or back of the couch and then attach a piece to the back of the throw pillow. Stick the pillow to the couch so it won't move.
Place a colorful throw on the back of the couch or over the arm to decorate a less-than perfect area. If the stuffing is protruding out of the seat cushions, fold the throw so it's large enough to cover the cushions, and spread it over the seating area. Tuck the slack into the back area and corners of the sofa seating area to secure it.
Encase the whole couch in a slipcover if the other decorating methods don't suffice. A slipcover will cover all flaws.