(RealSimple.com) -- Avoid common errors, and keep your four-legged pal healthy and well-behaved.

Mistake 1: Buying a pet spontaneously

Why this is a mistake: That doggie in the window may be darling, but he might not be the right fit for your family or lifestyle.

How to avoid it: Fully inform yourself before you bring home a pet. Every dog or cat has its own needs, some of which are specific to the breed. Terriers tend to dig; Abyssinians explore and climb. If there's a breed that interests you, read up on it (try the website of the American Kennel Club or the Cat Fanciers Association, talk to owners, and get to know someone else's Border collie or Persian.

That said, not every dog or cat is typical of its breed, so "ask about the pet's history, health, and temperament," says Stephanie Shain, a director at the Humane Society of the United States. When dealing with a breeder, you should be shown where the pet was raised and meet his parents.

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Mistake 2: Skipping obedience training

Why this is a mistake: Bad habits can be difficult to train out of a pet. So unless you have the know-how to school an animal, you need the help of a pro.

How to avoid it: Even before a puppy starts formal training, teach him simple commands, such as sit and stay. A puppy can begin formal training at eight weeks (and ideally before 12 weeks), after he has had his shots.

"Between the ages of 8 and 16 weeks, puppies readily absorb information about the world around them," says Andrea Arden, author of Dog-Friendly Training. To help a dog stick with good behaviors, every few years take him for a refresher course. (Find one in your area at the Association of Pet Dog Trainers.)

Mistake 3: Being inconsistent with the rules

Why this is a mistake: If one child lets Fifi on the bed and another punishes her for it, the animal will be confused. Bad behavior is inevitable.

How to avoid it: Make sure everyone in your household knows -- and follows --the rules, says Arden. "You want your dog to sit before eating a treat? You don't want your kitten to pounce on your hands? Then figure out a system that will help your pet succeed." Pets thrive with a sense of order, so discuss with your family when yours should be fed, exercised, and even given a treat.

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Mistake 4: Dispensing too many free treats

Why this is a mistake: Treats lose their training value if your pet gets them for no reason.

How to avoid it: "Think of treats as currency given to a pet to reward good behavior," says Marty Becker, a veterinarian and a coeditor of Petconnection.com. Assign each type of treat a value, and pay according to how well your pet behaves. Kibble is worth a dollar; a chicken strip, five; bologna, 10.

"But it's important to not pay off the good behavior all the time," Becker says. "That way, your dog will always hope he might get that piece of bologna, and he'll eventually perform without seeing a treat."

Mistake 5: Neglecting to socialize your pet

Why this is a mistake: Pets that aren't exposed to a variety of animals and people at a very young age can develop fears and aggressive behavior.

How to avoid it: Introduce your pet to adults, kids, animals, and environments so he'll take every novelty in stride. It's optimal for a pet to start the process before you bring him home, since the critical socialization period is early in life.

"For a dog, it's between the ages of 3 and 12 weeks. For cats, it's between 2 and 8 weeks," says Nicholas Dodman, director of the Animal Behavior Clinic at the Tufts Cummings School of Veterinary Medicine, in North Grafton, Massachusetts. The breeder or the shelter's adoption counselor can tell you how much socialization an animal has had.

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Mistake 6: Skimping on exercise

Why this is a mistake: Pets have pent-up energy that needs to be unleashed through physical activity. Otherwise it will be channeled into barking, jumping, or even hostile behavior.

How to avoid it: "Walk your dog at least twice a day for a minimum of 30 minutes each time," says Cesar Millan, host of The Dog Whisperer, on the National Geographic Channel. "To your dog, that's a primal activity -- birds fly, fish swim, and dogs walk."

Pamela Reid, vice president of the ASPCA's Animal-Behavior Center in Urbana, Illinois, recommends that dogs get at least 40 minutes of aerobic exercise daily. "Dogs need more exercise than people do," says Reid. Try running or biking with your dog or playing fetch or Frisbee. With a cat, "you can't take her jogging, but before and after work, give her 10 to 20 minutes of playtime," says Reid.

Mistake 7: Neglecting to keep your pet mentally active

Why this is a mistake: Bored pets are more likely to get into trouble.

How to avoid it: Give your pets something to do. For a dog, that can mean having him hunt for food. Place a meal or treats in spots around the house for him to sniff out, or "feed him out of a food-dispensing puzzle toy instead of his bowl," says Andrea Arden.

Keep a cat engaged with simple amusements, like a toy mouse dangling from a string. "You can stimulate your cat visually by placing a bird feeder outside a window, or setting a lava lamp on a shelf," says Arden Moore, author of The Cat Behavior Answer Book.

Mistake 8: Leaving a pet alone for too long

Why this is a mistake: A lack of proper companionship can lead to separation anxiety and destructive behaviors.

How to avoid it: "Don't leave a puppy alone for eight hours," says Reid. Hire someone to watch him or drop him off at a doggie day-care center. Your puppy will need to learn how to be alone for a few hours each day, however, so "teach him to self-pacify almost immediately," says Andrea Arden.

Put him in a crate (or leash him to a stable object) a foot or two away from you, then gradually increase the distance over the course of a week. Then make sure that he spends escalating amounts of time alone in his crate or confined to a room. Break up the day for dogs of any age with a visit from a dog walker or a neighbor, and give your pet access to toys and visual stimuli. Unlike puppies, kittens can be left alone, but they should have access to toys and visual stimuli.

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Mistake 9: Failing to make your home pet-friendly

Why this is a mistake: A cat without a proper litter box will just use the carpet. A dog without a cozy bed will end up on the couch.

How to avoid it: Location is key with a litter box. "A cat doesn't want to travel a long way to go to the bathroom any more than you do," says Mieshelle Nagelschneider, a feline behaviorist and a consultant at the Cat Behavior Clinic, near Portland, Oregon.

Place litter boxes (one per cat, if you own a few, plus one box they can share, says Moore) in quiet areas throughout your home. Plug in a night-light beside each one so your cat can find it in the dark. Cats dislike strong odors (even air freshener), so use uncovered boxes and unscented litter and scoop out each box every day.

Dogs are far less persnickety about where they relieve themselves, but do them the favor of regularly picking up the poop in the backyard. Cats and dogs also need spots where they can cuddle up and feel safe. "A dog needs a crate like a teenager needs a room," says Dodman. Provide a crate or a cozy bed, and make it taboo for your family to pester the dog while he's in it. Cats naturally want to climb to an optimal vantage point, so set up a place where yours can look out a window.

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Mistake 10: Punishing your pet

Why this is a mistake: You might think Chewie knows you're screaming at him because he ate the loaf of bread on the counter, but he won't connect your behavior with his action.

How to avoid it: Never physically punish your pet; he'll just learn to fear you. It's OK to startle a pet out of a behavior, but only if you catch him in the act. Command him with a firm "No!" or "Down!" and he'll connect the reaction with what he's doing and learn that it's not OK.

Otherwise, the punishment should come from the environment. Teach a cat or a dog to stay off the counter, say, by arranging sheet pans in a pile that will clatter to the floor if he jumps up. The counter, not you, will become the thing to fear.

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