I wanted to explain, briefly, what each tool in the dog training toolkit is used for. I'm going to start with the tools I use and recommend, and then move on to the ones I don't. However, I'm not going to start a debate, or vilify other trainers who do use them.
Tools I use and recommend:
Now I wanted to get into the tools that I have used before, and don't recommend:
In short, all tools are bandaids, and don't replace proper training. Focus on doing the work, not on what tool is used. Watch the behavior of the dog: is the dog happy, eager to work with this person, and performing well? Is the owner pleased with the dog's wellbeing and training? Then I have no complaints. However, I feel it is my duty to introduce methods and tools that are less aversive, and still accomplish the training goals for the dog efficiently and effectively.