Always remember that you are dealing with a very immature young animal. Be realistic, flexible, patient and always fair during puppy training sessions. Your puppy doesn't just automatically know this stuff! It's all new to him and he is bound to have the odd slip up and mistake along the way. Don't worry about these mistakes, just move on and do your best to prevent them in the future.
Remember that training is an ongoing process. You will never be completely finished. It is important to keep working on obedience training throughout the life of your dog. People who learn a language at a young age but stop speaking that language may forget much of it as they grow older. The same goes for your dog: use it or lose it. Running through even the most basic tricks and commands will help them stay fresh in your dog's mind. Plus, it's a great way to spend time with your dog.
The first method is called capturing. Stand in front of your puppy holding some of his dog food or treats. Wait for him to sit – say “yes” and give him a treat. Then step backwards or sideways to encourage him to stand and wait for him to sit. Give another treat as soon as they sit. After a few repetitions, you can begin saying “sit” right as he begins to sit.
Any area that the pup has access to must be kept clear and clean. Put out of puppy's reach anything you don't want him to chew or destroy. Do not allow your puppy to have unsupervised access to 'unchewables.' Do not chase the puppy in an attempt to take something away. Instead provide puppy with her own toys and teach her how to play with them exclusively.