First off, make sure that you remove anything off the floor or away from the dog's reach, while he's in this stage. When your dog is reliable about not chewing your things, you can start to introduce these items back to their places, but while your dog doesn't know better, you're setting him up to fail, leaving everything as is.
- You want to make sure that you keep your dog well exercised. A dog that has mental stimulation and the proper exercise that he needs, will not feel the need to chew to release that energy.
- Provide plenty of chew toys, treats, and other items that are appropriate for your dog. You want to make sure that you do not give him anything that could resemble something you don't want chewed. For example, if you don't care that your pup chews on an old slipper because you have new ones, you'll need to make the old ones different than the new ones. Same with socks; tie knots in socks to make them different from good socks you do not want gnawed on.
When you catch your pup with something that he's not supposed to have, and you will catch him at some point or another, you'll want to quickly reprimand him and give him a safe toy or a treat. Make the toy very exciting, as you'll want the dog to think whatever you're trying to give him is better than whatever he currently has.
If the problem is more when you're not around the dog chews, that's is even easier to help.... All you'll need to do is put the dog in a crate or outside when you are not home. This will prevent the dog from chewing your things when you cannot reprimand him.