Cats are well known for their independent personalities. The old joke that a dog comes when called, but that a cat takes a message and gets back to you has stood the test of time for a reason cats do what they want, when it suits them.
This doesnt mean, however, that all is lost if your cat is behaving in a way thats problematic. You can discipline a cat. The three most powerful tools in your arsenal are immediate response, removing the temptation and distraction.
But before we go any farther, lets be clear do not ever use physical punishment to discipline a cat. Striking, hitting or spanking a cat simply doesnt work and can be harmful to the cat. Even a swat or tap with a finger can be too much and encourage a cat to become aggressive. Another thing to keep in mind is that behaviors that are problematic for us such as scratching the furniture are normal behaviors for the cat. The cat shouldnt be punished for exhibiting normal behavior, but rather, that behavior should be redirected.
Lets take then, for example, scratching the furniture. A cat has a natural need to scratch we just want to direct it towards a more appropriate outlet. Our first tool is immediate response. This means that you must act as soon as you see your cat beginning to assume the position for scratching the furniture. Some experts suggesting using a spray bottle filled with water to lightly spritz your cat. Since most cats don't like water, this can provide negative reinforcement. However, to be effective, you must be there every time, and your cat has to find the water spritz negative enough to want to change her behavior. Chances are your cat is more likely to just wait until you're not around.
A better choice is to intervene immediately by providing an appropriate distraction. First, choose a sound like a growl or a hiss and make the noise loudly when your cat begins to engage in negative behaviors. Its important to make the sound as much unlike your normal voice or praise as possible. Once your cat is distracted, encourage her to use her scratching post, instead of your sofa.
You should also remove the temptation for misbehavior. In our current example, your cat scratches your furniture because its the right height and she likes the feel of it. Try covering your furniture with a throw or an acrylic shield, and shell no longer find scratching your furniture to be so enjoyable. Cats also like to stretch, so make sure their scratching posts are tall enough to allow them to stretch fully. If your cat cant get what she needs from her current scratching pole, shell take out her frustrations on the items that feel better to her.
Also, be aware that behaviors that look like misbehaviors may not always be such. For example, if your cat relieves herself outside her litter box, she could be doing it intentionally to indicate her displeasure with you or because you haven't kept her litter box clean enough to suit her. It could also be a sign of a urinary tract infection. The first thing you should do is clean her litter box thoroughly, using a product that removes odors. If she still continues to relieve herself outside of the litter box, have her evaluated by your veterinarian. Only after medical problems have been ruled out should you begin to attempt to modify her behavior.