Principles Of Preventative Training
The idea is simple. Avoid leaving your dog unsupervised where he can get into trouble; with this approach, he will learn which activities are allowed without learning those that are forbidden. In other words, it is easier to teach your puppy to chew his toys than to teach him to stop chewing on your couch.

If your dog is left unsupervised and does unwanted things, he likely believes these things are okay because he enjoys doing them and no one is there to say anything different. You should not correct a dog after the fact – dogs cannot connect a correction with something they did hours, minutes or even seconds ago. Until you catch your dog in the act, the unwanted behavior is reinforced every time he repeats it.

Practicing Preventative Training
First off, plan to spend a lot of time with your dog for the first several months after you bring your dog home, and make sure you have a crate for your dog. (Read about Crate Training for more information) 

• Confine your dog to the room you're in and litter it generously with chew toys.
• If your dog starts heading toward trouble, distract him with an appropriate toy and praise him when he takes it.
• If your dog is already into trouble, interrupt him with a firm ‘No!’; then, when the dog stops, offer a toy and praise him for interest in it or give an obedience command and praise your dog for obeying.
• When you can’t be around, keep your dog confined in his crate, a pen or in a small, dog-proof area.

It’s that simple, and if done properly, it’s extremely effective because:

• It doesn’t allow bad habits to form; so you don’t need to correct them later.
• It helps build a strong bond between you and your dog.
  

Do’s and Don’ts

DO use the right tone of voice to communicate: higher pitched for praise; matter-of-fact for commands; lower tones to show displeasure.

DON’T hit your dog. Dogs and puppies do not understand being hit or grabbed. They will only learn they cannot trust you and learn to fear you, making them even harder to train.

DO provide opportunities for daily physical exercise so that your dog can expend energy in appropriate ways.

DO praise your dog warmly and frequently for doing the right thing. This will help your dog to make the right choices in the future and besides, it’s fun!

Getting off to the right start
As soon as you bring your puppy home, you should make it a habit to always reward appropriate behaviors (including times when your puppy is calmly sitting or laying down) as soon as they occur by providing praise, affection or even a kibble of food. Rewarding this type of behavior will help your puppy learn acceptable behaviors early on and will set the foundation for pleasant learning experiences going forward.