If you enjoy duck hunting, you will find that it's a great help to have a trained bird dog with you. Training your dog is fairy easy, but can take months depending on the breed and temperament of your dog.
Pick a breed of dog that has proven hunting ability. Great bird dog breeds include German pointer, Labrador retriever, English setter, Irish setter and Hungarian Vizsla.
Train your dog not to be gun-shy. Many puppies and untrained dogs are startled by the sound of gunfire. To train your dog to ignore the sound of a gunshot, simply take two pieces of 2x4 and clap them together, then immediately give your dog a treat. Repeat over 10 minutes once or twice a day. Over the course of several weeks, you can train your dog to associate loud noises with positive reinforcement.
Begin integrating the training dummy into your training sessions. A training dummy is simply a canvas cylinder, available at most pet supply stores. If you haven't already trained your dog to fetch, do so now. Most dogs (especially hunting dogs) have a natural talent for this.
Think of the hunting process as three commands: hold (i.e., holding the duck in the mouth without eating it), carry and release. Associate one clear, brief command with each concept, such as "Easy" for hold, "fetch" or "go get it" for carry, and "drop it" or "leave it" for release. Practice the commands with the training dummy. Always reward your dog with praise and a dog treat. If you are concerned that your dog is biting too hard (and thus running the risk of rendering your bird inedible), you can try replacing the training dummy with your hand. This will give you a sense of how hard the dog is biting down, and you can take measures from there to correct the bite. Alternatively, try a vegetable such as a cucumber.
Take your dog hunting for real-life experience. The first time you take your dog hunting, go by yourself instead of with your hunting buddies. Other people or their dogs may be too distracting for a novice dog. See how your dog performs, and adjust his training accordingly. Having dog treats to reward your dog with will help teach him proper behavior, and also deter him from devouring your duck.