Some folks are under the
impression that if you're going to have a
pet cat that lives indoors, he's going to need to be
declawed. Not so!
Declawing can be responsible for more problems than it solves. Some cats have absolutely no trouble with it, but many others don't have the same
luck.
The most effective training technique I've found for teaching cats where to and where not to scratch is so simple it's almost embarrassing. Almost. Firstly, a good cat owner realizes that cats have claws for a reason, and that they need somewhere to scratch. So an appropriate outlet for this particular cat-clawing energy must be provided. A carpeted scratching post isn't as great an idea as the people in the pet stores would have you believe. Cats are not interior decorators. It is difficult for them to discern between the carpet it's okay to scratch up and the carpet that covers your floor. A big piece of corrugated cardboard tacked to the wall looks hideous, but it does a great job. Cats love to scratch that stuff. A big tree limb is also a good idea, and it's as cost-effective as the cardboard. You'll just have to get used to the ugliness!
There. Now Fluffy has a place or two where he is allowed to scratch. The trick now is to keep him away from your sofa and recliner and dining room table. Super-sticky double-sided tape does the trick for most cats. You just put it on things you want your cat to leave alone and let him discover the unpleasant stickiness on his own. Don't say anything to him, for the love of all that is good and holy! Your tantrums will only teach him that a) you are extremely weird and maybe a little scary, and b) certain behaviors are only rewarding when you aren't there. In essence, you can teach your cat to be "sneaky". (At least, it will look like sneakiness to you.)
Leave the tape on the furniture for a long time. You'll have to change it now and then because icky stuff floating around in the air will get all over it, it will look like hell, and it will lose its stickiness. Eventually, your cat will realize that he's got a good place to scratch, and that the other places he chooses are crappy. Therefore, he won't even want to scratch the furniture after a while, and you can take the tape off. Training a cat (and really, a dog, or a kid, or a spouse...) is most effective when you can get your subject to believe that whatever you're trying to teach them is something they've come up with on their own. This way, behaviors become self-reinforcing. Exhibiting them is rewarding in and of itself. Then, you don't have to keep re-teaching.