Hello from Georgia,
I was recently involved in a discussion with several guys, and the subject of dog training came up. I quietly listened and it became obvious that only one of the 4 other guys had ever had any experience in training a working dog. After a while, I decided to add my opinions as I will do here.
The easiest way on Earth to teach a dog how to hunt is to simply take him with other dogs that are doing what you want to do. This works for all dogs that are from suitable working lines. I have been around catch and bay dogs as long as I can remember.(well over 30 years now) It just seems natural to bring a young dog along for the hunt. Allowing a green dog to work with the hardened veterans will NATURALLY teach a dog to do as they see. It is even possible to mold a dog to do precisely what you want him to do in several different roles. A pig catching/bay dog is a valuable tool, and when there are other dogs ready and willing to learn, well, it is a beautiful thing.
Although I have never hunted birds much, I do know about bird dogs. I live about 15 mins from Waynesboro, GA, The Bird Dog Capitol Of The World. This happens to be the home for some of the most prestigious field trials in the world. There are even some very exclusive private trials that include both hunting and dog shows/certifications. I have had the opportunity to meet a few of the best trainers and they agree with the methods I believe in. Sure for show points, and "qualifications" there has to be a strict training, but to show a dog how to hunt just let them go with the working dogs.
I can not imagine any working class beagle getting lost on a bunny trail when there are 5 others to show him the way.
A lab will follow another dog into the water with no coaching at all.
This way of training is also productive as well. If the dogs do there job , there should be a few opportunities to harvest some game the first time a new dog goes out. This is rewarding to both the hunter, and especially to the dog. The breed of dog and the game hunted are not nearly as important as the chance to go out and do what a dog does. I am truly fulfilled when I have the opportunity to go on a hunt with some good dogs.
Dave