TIP #1: DESTRUCTIVE CHEWING
If you give your puppy the run of the house and he learns to chew on carpets, sofa cushions, and coffee table legs, you will likely end up with a dog who chooses to exercise his jaws and teeth on inappropriate objects for years to come. You'll find yourself crating him frequently even as an adult dog, or worse, exiling him to a lonely life in the backyard, where he can chew only on lawn furniture, loose fence boards, and the edges of your deck and hot tub.
Instead, focus your dog's fangs on approved chew toys at an early age and manage him well to prevent access to your stuff. In this way, he'll earn house privileges much sooner in life.
- The Whole Dog Journal
TIP #2: BREAK THE CHAIN
A behavior chain is an event in which units of behavior occur in sequences and are linked together by learned cues. Behavior chains are needed, say, if you want to train your dog a complex task like getting a beverage out of the frig. But they can also cause problems, too. For instance, if you always ask your dog to sit before you cue him to down, eventually he will 'chain' them together and the Sit cue will cause him to automatically lie down.
If you want to break an unwanted behavior chain you could insert a gratuitous pause between the cues/behaviors or, using the Sit/Down example, you could ask your dog to lie down from a standing position.
Jeff Dentler, CPDT-KA, CTDI