Positive reinforcement is the most effective and fair approach to training a kitten or cat. Some people use “pure” positive reinforcement, meaning they don't use any corrections during training. Others use positive reinforcement for desired behaviors and gentle corrections for the undesirable ones.
Positive reinforcement is the process of rewarding your cat with something she likes for doing what you want her to do, such as praise and a treat for coming when you call her.
One popular form of training using positive reinforcement is clicker training, so-called because you use a handheld clicker to tell your cat when he's done something correctly. Clicker training has become popular among dog trainers, but it is effective with many kinds of animals, including cats. A complete discussion of clicker training (based on principles of operant conditioning) fills entire books, so I won't go into the details here. If you're interested in trying this punishment-free method with your cat, check out Karen Prior's book Don't Shoot the Dog.
In the end, though, you don't need gadgets to train your cat. You just need consistency and a way to tell him when he does the right thing. Consistency means you and everyone else in your household allow and disallow the same behaviors. If you shoo your cat off the kitchen table and someone else cuddles him there half an hour later, he'll be confused about whether he's allowed to be there or not. Rewards—treats, cuddles, toys—tell your cat that a particular behavior earns him something he likes.
Training should begin as soon as you bring your kitten or cat home. If you have a kitten, begin gentle handling and training right away. Use frequent sessions, and remember that kittens have short attention spans, so a few minutes at a time are plenty. If you have an older cat, sessions can be a bit longer, especially once your cat gets used to being trained, but don't expect even an adult to give you his undivided attention for more than 5 to 10 minutes at a time. Focus on one behavior during each session and keep training fun. If your kitty does what you ask two or three times, quit for a while and play with him. You can do more training a little later. Learning is hard work and better accomplished in small amounts.
Teach your cat to let you restrain her—this will be useful for general grooming and routine vet visits and might be critical in an emergency. Begin with very short sessions of holding, and slowly increase the length of time until you can hold her still without a fight for 5 minutes or so. She will learn to trust that you have nothing sinister in mind when you hold her, and that will help you teach her to let you groom and examine her (see Keeping Up with Your Cat's Hygiene).
Never, ever hit your cat, not with your hand, not with a flyswatter, not with anything. Hitting him won't teach him anything you want him to learn. He will learn, instead, to be afraid of people and he might become shy, nervous, and withdrawn. He might try to fight back, biting or swatting out of fear. Either way, you'll have an unhappy cat on your hands, and you won't be very happy, either.
If you can't watch your kitten or new adult cat, confine him to a room or a cat cage. It's easier to prevent unwanted behaviors than to correct them after they become bad habits.
Training an animal can be frustrating at times, but it can also be highly rewarding. If you (or your cat) are getting frustrated, quit for a while. Relax. Come back to the lesson when you're in a better mood. Most of all, respect and enjoy your cat.
Litter Box Training
Most kittens and cats are naturally clean about their toilet practices. Mother cats normally teach their offspring to use the “proper facilities,” but even kittens who miss out on Mom's guidance usually learn proper potty etiquette easily. Still, you can help encourage good habits.
Many different types of litter boxes are available, from the simple, inexpensive plastic model to the pricey, self-cleaning electronic contraption. Fancy boxes might appeal to cat owners, but all your cat really needs is a litter box that's large enough for her to be able to fit into it comfortably, turn around, and dig in the litter.
If you have a very young kitten, he might need a little extra help with potty training. When you can't supervise him, confine him to one room or a cat cage with access to a litter box. Place him in the litter box immediately after meals, naps, and play times, when he's likely to need to go. If he's too small to climb in and out of an adult-size litter box, give him litter in a low-sided aluminum or plastic pan.
Place the litter box in a quiet, low-traffic area. If you have a dog, find a way to keep the dog out of the litter box—many dogs are attracted to the rich, high-protein odor of cat feces. If you have more than one cat, you might want to provide more than one litter box—the cats will decide how to divvy them up. (I've had cats who each used individual boxes, and other cats who both used both boxes, one for urine and one for feces.) If you use a single box for multiple cats, remove waste at least once a day and clean the box once or twice a week. If your cat seems to track litter out of the box, place the box on a washable rug or plastic mat to catch the litter.