Provide your cats with something appropriate for scratching. Scratching posts come in all sizes and most are covered in carpet or sisal, which cats especially like to scratch. Rub some catnip on the post, and place it where the cats like to hang out. That might be next to their food bowl, in front of the fireplace or next to a window. Catch the cats in the act of using the scratching post and give lots of praise and cat treats.
Attach something aversive to the cats on the sofa where they like to scratch --- double-sided sticky tape, aluminum foil, sheets of sandpaper or a plastic carpet runner with the pointy side up. If that doesn't work, try some odors that most cats don't like. Attach some cotton balls to the sofa that have been soaked in citrus, menthol, cologne or a muscle rub. If any of these things seem to be working, leave them in place until you are sure the cats have lost interest in your furniture.
Place nail caps on your cats. Nail caps fit over the cats nails and prevent them from scratching. The caps eventually fall off and hopefully the scratching habit is cured by then. You can find them in any large pet store or on the Internet.
Confine your cats to their own room. If you have a spare room, or you're willing to share an office with your cats, put the scratching post and all other cat possessions in the room --- toys, food and water and litter box. Keep your cats in the room until they stake it out as their territory --- and they will. This may take a month or two. Once they lay claim to it, they might lose interest in your furniture and prefer their room and scratching post to all else. Don't put the cats in a room without a window. Cats love to watch the world outside, and it keeps them content.
Talk to your veterinarian. Declawing a cat is a controversial topic. Some veterinarians refuse to do the procedure. Many cat owners refuse to declaw their cats. It's something to consider if you've tried everything suggested and none of it works. When Dr. Rusty Gailor, DVM of Gailor Animal Hospital in Louisville, Kentucky, was asked his opinion on cat declawing, he replied, "If it means the difference between the cat having a good home or no home at all, I would rather declaw the cat." According to Dr. Pitcairn, DVM, PhD., and author of "Complete Secrets To The Natural Health of Dogs & Cats," declawing a cat can impair its balance, cause it to feel nervous and defenseless and lower its immunity to disease due to stress. "Declawing your cat is not a suitable solution to scratching problems," states Dr. Pitcairn.
Make a scratching post for your cats. According to Dr. Pitcairn, the best scratching posts are covered in sisal.
Nail an untreated 4-by-4 post cut 2 to 3 feet long to a base of 1/2-inch plywood about 16 inches by 16 inches.
Wrap the post with sisal rope or a piece of carpet turned inside out. Turning the carpet inside out makes it more appealing to cats because they prefer rough surfaces to soft.