Sometimes (a lot of times) when people bring their dog for training it's because the dog is not doing what the human wants.
Does the dog understand the desired behavior? Is the dog able to produce the desired behavior? Can the dog associate the behavior with the command? Does the desired behavior earn a better reward than other options?
If you were offered a job that payed better, payed more often, had better working conditions, greater chances for success, and more interesting and meaningful work, wouldn't you take it? And what if you were paid in cash?
Or what if you were already a millionaire and somebody asked you to do something you didn't want to do, and they wanted to pay you a dollar?
Your dog is not that different. While dogs do not have cause and effect like humans, they have a remarkable ability to discern what goes with what. If every time they sit they get a piece of a hot dog, most dogs will spontaneously offer a "sit" after just a few repetitions.
"Most dogs" is the point of this story. Most dogs will respond to food as a reward -- some dogs don't care about food that much, but will do anything for a ball or a tug toy, some don't care much about food or play but live for affection. So it is important to figure out what your dog finds rewarding; this isn't about what you like or what you think the dog should like, it's about what the dog likes.
And some dogs with behavior problems don't respond to much of anything. More often than not these are the dogs that are free-fed, walked on a retractable leash, sleep on the owner's bed, receive affection randomly and often, do not receive effective corrections, are soothed and coddled when they display anxious or fearful behavior, and they are "distracted" with treats and attention when their behavior becomes unmanageable.
Let's translate that -- "I eat whenever I want, I walk, run, or jump wherever I want, I sleep wherever I want, preferably in the highest-status place, I have no connection to anyone in particular, I receive praise just for existing, I am not required to control my own emotional state, there is no connection between my behavior and outcomes except when I act afraid, and I am rewarded especially well when I behave in an outrageous manner."
The first step in humane training is to have a dog that is trainable, that is, a dog who wants something, so that you can trade things that he or she wants for behaviors that you want. So in addition to figuring out what your particular dog finds rewarding, it is important that your dog understands that it isn't free, they have to work for it.
To the canine mind, this exchange is the beginning of reciprocity, trust, safety, and partnership.