Selecting the right collar is partially determined by what works best for you and for your dog. If you have a dog who is easy to walk and doesn’t pull, a flat nylon or leather buckle collar will do just fine. If your dog pulls on a walk or gets excited and lunges when he sees other dogs, you may have more success with a correction collar such as a martingale or prong collar.
All that being said, a correction collar (as with any tool you may use with a dog) should be considered a temporary aid until you get your own Leadership skills up to par. Once you’re able to demonstrate Leadership to your dog, you’ll succeed no matter what tool you’re using.