Dog training books, courses, and programs vary widely, as do the concepts and approaches of various dog trainers. However, there are basic attitudes and skills to look for in finding a universal dog trainer. You can also browse to https://www.tractiondogtraining.com/ and hire a dog trainer in Boulder.
Although dogs have a human-like character, they are not simple-minded or arrogant like humans. Their brains naturally work in a way that responds to a consistent, persistent, and patient learning style. If you can find a dog trainer with these characteristics early on, you will be ahead of the curve.
Above all, the behavior of a good dog trainer should be calm, limited, and focused on the training task. It cannot be a hit-or-miss thing. Some lessons are picked up quickly, others can take weeks of repetition to finally master. Some dogs and/or owners require extreme patience and composure.
Find a dog trainer who is willing to explain clearly what methods they use and why, what their goals and objectives are, and who does it in a friendly and patient manner. If your trainer is good with your dog but has trouble communicating with you, half the training battle is over. You cannot continue training your dog at home and any discrepancies will confuse your dog.
Of course, there are many variables, such as different breeds and individuals of dogs and the personality of their owners, that are relevant to successful training. Observe how your trainer interacts with different dogs and different owners. This is probably the best way of determining his/her ability to adapt and adjust but still get results.