Pet training is subject to a guru effect that has significant impact on families with animals. If you are my age you'll remember The Monks of Newskete and Barbara Woodhouse. If you are bit younger you'll know Ceasar Milan and Victoria Stillwell. These dog training gurus usually have books or TV shows that proclaim the secret to training your dog, usually with little or no effort, just a magic formula for the perfect dog. There are always catch phrases, too, like Walkies, Let 'em know who's boss, Click 'n Treat, the Seven Games. Horse training was where the "whisperer" moniker was born.
What you may not know is there are pet training experts who have been around much longer than the latest fad and though they often have books read by training geeks, they don't usually have TV shows because they don't profess magic. Dr. Ian Dunbar and William Campbell, Suzanne Clothier and Jean Donaldson have all been training dogs and researching the effects and methods of training all animals for decades and they all say the same thing. It's the relationship that makes the difference.
If you are not interesting to your dog you probably will need a gimmick to train him but it won't work in an emergency and that's really what matters. While I prefer methods of training that profess to be based on positive reinforcement to capture a new behavior and then life rewards to promote good behavior, it amazes me how far from this the actual lessons can be while making the dog owner feel better about training.
For example, if your dog does not sit when you ask he either does not know what you are asking, doesn't care what you want or is distracted by something better. The gurus make all this go away by giving you theories about dominance or clickers or environmental enrichment. And while many of these tools are a part of dog training, these three problems (understanding, interest, or attention) won't change.
If your dog doesn't know what you want.
Go back to the basics. If there is a location or activity during which your dog responds to a particular cue well, go there and do that. Remove all extraneous information and practice. Most dogs sit in the kitchen when you are leaning forward near the treat jar with something in your hand. Move away from the treat jar, stand up straight. Once you conquer that, try different rooms, then outside. Back up if you need to. Most professional trainers are shocked when they see videos of their training fails. It can be quite obvious what the dog thinks when you see an interaction from afar. He really might be unsure of what you are asking.
If your dog doesn't care what you want.
If you have a dog door and hand over your fries anytime your dog nudges you, there is really no reason for him to care what you like or don't as long as you do his bidding. We've mentioned this before as a particular problem for sight hounds. Their ability to prioritize is often viewed as inattention, lack of intelligence, or downright defiance. But the truth is- he who controls the door handle rules. And if whether your dog can run or chase things is up to you, he will not only do what you ask he will try to figure out what you want. Control your dog's access to the things he wants to do and offer them often, in exchange for responding to your requests for just about anything.
If he is distracted by something better.
This is a tough one and boils down to the very reason gurus make a splash. Wouldn't you rather believe that a particular recipe of exercise and special noises could train your dog than accept that practice makes perfect? And you can't just practice right before you go to an event where the skills are needed, either. The good news is you can practice as little as three times per week for 5-10 minutes and expect to see change. But to practice you'll have to set up challenges. And this is where people fall down. A dog who barks at other dogs (barking = better than being quiet) needs to practice NOT barking at other dogs. Taking him near other dogs makes him bark thus you get mad and leave. He learns barking gets him out of situations he doesn't like. Instead, set up at distance from the local PetSmart parking lot where your dog can succeed at not barking. REWARD HIM with something he will absolutely understand is a gift, a joy, an actual reward. Once he is clear that to get that reward he must NOT bark, associate a word with that quiet observance. Practice getting closer until your dog 1. knows what you want when you say that word, 2. cares that you want it and 3. can do it when it's hard
I wish there were a magic formula (target training comes close) or an all knowing scientist who would divulge the secret (the real ones know it's not a secret -just a little work) but instead it's the usual bad news. You get out what you put in.