Do not punish your cat for scratching, or for anything you see as bad cat behavior. Punishment is unlikely to have any beneficial effect whatsoever. Your cat simply will not understand if you try to punish her in any way for something she has done, cats do not relate punishment to the “crime”, they are far more likely to relate the punishment to you!
Even cats that are allowed outdoors will sometimes scratch your furniture, although not as often as indoor only cats. Trees are the natural scratching surface for cats, and to a cat that is kept inside the arms and legs of chairs, and other furniture, sure seems like a suitable alternative!
The most common answer to this cat scratching problem is, of course, a scratching post, or even two. A great variety of posts are available from pet stores and online pet suppliers. They are fairly simple things to construct, but if you do make one yourself, be certain that there are no nails or other sharp things left sticking out to snag your kitty. And make sure that the base is heavy enough, if it falls over your cat will not want to use it again. Cover the post with rope rather than with carpet, the last thing that you want to do is give your cat the message that it is OK for her to scratch carpet!
Ensure that the scratching post is tall enough for your cat, cats like to stretch when they scratch it exercises their muscles. Spread cat nip on one of the platforms to make the post even more attractive to your cat, and attach a few toys to the post so that they hang down temptingly.
If you just put a scratching post down in front of your cat, what is she going to make of it? It may look like a good place to scratch and claw, but then she has been mildly admonished for scratching at things. You may have to teach your cat that it is OK to use the post, that it will not upset you, that scratching the post is what you want her to do.
Every time that you see your kitty about to scratch your furniture, pick her up and gently place her in front of the post. If she decides to use it give her plenty of praise and encouragement. Cover the furniture she scratches with some netting, or aluminum foil. Your cat should soon learn that it is unpleasant to scratch furniture, but great to scratch her post.
If your cat is in the habit of scratching wooden furniture, or doorjambs then strong smelling polish, or vinegar are often good deterrents, if you try the vinegar, check that it won’t harm the surface of the wood. Some cat owners report that half an orange or lemon place by the problem has good results. Do not remove the disagreeable smells or covering from your furniture until your cat has been using her scratching post for about a month.
If your cat is a horizontal scratcher rather than vertical one, in other words she scratches up your carpet or expensive parquet flooring, try persuading her to use a piece of rush matting, tape the matting down to prevent the mat moving.
What ever you do to solve your cat scratching problem, do not even think of declawing, it is barbaric.