My tuxedo cat used to be a chronic scratcher. I bought a nice carpeted cat scratch and he took right to it. Also keeping his nails shorter helped a lot.
Generally, a scratching post or some sort of hard yet not impermeable material should detract cats from scratching furniture. Also, consider putting guards on exposed parts of the furniture when possible.
I own two "mutt" cats, both of whom have scratched furniture at times. If I catch them at it, I sharply yell, "NO!" and squirt them with a water bottle. If I notice a place that they've been scratching, I cover it in aluminum foil. They hate the feel and sound of the foil.
We have a Domestic Short Hair Tabby and we've found that putting a scratching post by the corner of a couch gives her all the opportunity to scratch that she needs. We rub it with catnip weekly so it stays attractive to her. We have one in the living room and one in the family room as those are the only places she's scratched furniture.
also see Prevent Your Cat from Scratching Furniture
also see Controlling Aggressive Cat Behavior
also see 8 Solutions to Cat Furniture Problems
also see Stopping a Cat From Scratching Furniture
also see Symptoms of Cat Scratch Disease
also see Using Nail Caps for Cats to Stop Destructive Scratching