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.
Dog training classes or private sessions can also be an addition to your own training program. The dog trainer can help you improve the program and customize it to your dog's learning style. Try to be as involved as possible when it comes to your dog's training. You and your dog will be a stronger team when you are directly involved in the training process.