A cat that is prone to scratching can be kept off furniture by providing alternatives or by making the furniture less appealing. If the cat cannot be kept from going onto furniture, then carefully trimming its claws or applying plastic caps over the claws will at least limit the damage caused.
Some alternative options for the cat to scratch include scratching posts, boards or even old and already damaged or unwanted furniture. In order to ensure that the cat will be happy with the transition, it is a good idea to match as closely as possible its favored kind of surface to scratch. For example, if the cat tends to scratch furniture legs or other wooden features, then a wooden piece of cat furniture would be the most suitable replacement. If the cat's preferred scratching surface is unclear, one can experiment with a range of materials, such as cardboard, sisal and upholstery.
Discouraging the cat from the existing furniture can be as simple as spraying a herbal or pheromone-based deterrent. The latter of these replaces the cat's own scent on an object so that it will no longer be considered its territory. Another simple method of discouraging cats from existing furniture is to change its texture with something unpleasant, such as sandpaper.