Destructive Chewing

Taking Control by Managing the Situation

Take responsibility for your own belongings: if you don't want it in your dog's month, don't make it available.
Keep clothing, shoes, books, trash, eyeglasses, and remote control devices out of your dog's reach
Don't confuse your dog by offering him shoes and socks as toys and then expecting him to distinguish between his shoes and yours.
Until he knows the household rules confine him when you're unable to keep an eye on him.
Give your dog plenty of time and attention.
If you catch your dog chewing on something he shouldn't interrupt the behavior with a loud noise, offer him an acceptable chew toy instead, and praise him lavishly when he takes the toy in his mouth.
Have realistic expectations. At some point your dog will inevitably chew up something you value; this is often part of the transition to a new home
Remember that your dog needs time to learn house rules and you need to remember to take precautions and keep things out of his reach.

Play, Boredom, or Social Isolation

Normal play behavior sometimes leads to destruction, as it may involve digging, chewing, shredding, or shaking objects. This is all because dogs investigate objects by pawing at them and exploring them with their mouths, they may also inadvertently damage items in their environment. Your dog may be chewing for entertainment if:

He's left alone for long periods without opportunities to interact with you.
His environment is relatively barren, lacking playmates or toys.
He's a puppy or adolescent (under three years old) and he doesn't have other outlets for his energy.
He's particularly active type of dog (like the herding or sporting breeds) who needs to be occupied to be happy.

Solutions

Play with your dog daily in a safe, fenced in area. Playing fetch is a great way to use up your dog's excess energy without wearing you out too!
Go for a walk! Walks shouldn't be just for "bathroom time".
On the leash walks are important opportunities for you and your dog to be together. Allow time for sniffing, exploring, instructions, and praise.
Teach your dog a few commands or tricks and practice them daily.
Dog training classes; are fun, and such classes teach commands important for your dog's safety and give you and your dog time to work toward a common goal.
Provide your dog with lots of appropriate toys. Rotate your dog's toys to refresh his interest in them.
Consider a good "doggie day care" program for two or three days a week to help your dog work off some of his excess energy.

Separation Anxiety

Dogs with separation anxiety tend to display behaviors that reflect a strong attachment to their owners. This includes following you from room to room, frantic greetings, and anxious response whenever you prepare to leave the house. Factors that can precipitate a separation anxiety problem include:

A change in the family's schedule that leaves your dog alone more often
A move to a new home
The death or loss of a family member or another family pet.
A period at a shelter or boarding kennel.
Remember: That these behaviors are not motivation

What Not to Do!

Punishment is rarely effective in resolving destructive behavior problems and may even make the problem worse. Never discipline your dog after the fact. Your dog doesn't know what he's done wrong; he only knows that you're upset. Punishment after the fact will not only fail to eliminate the undesirable behavior, but may also provoke other undesirable behaviors.