If you read the last two entries in the "power series," you've so far learned that both handlers and their dogs bring to the table their own levels of power and self-determination to the table. To be a great handler, you can use your observation and experience with dogs to either raise or lower your power as needed, depending on what a specific dog needs at any specific time.
Start by just looking at your dog and his body language. A good guideline is that the more active your dogs body language and movement, the more power you can use in your handling. The less active your dogs body language and movement, the lower power you need to use.
Often when I approach a specific dog in class, to show the owner a technique, the dog is just sitting there staring at me. Sometimes it even looks concerned or anxious about my approach. ("Who IS this woman? Is this safe?") At this moment, this dog is showing very low power. So the last thing I'm going to do is march right in, grab the leash, and start directing it around! Instead I will do specific things to lower my own power -- maybe kneel down (make myself smaller), smile and talk nicely, invite the dog in to my space, not do any commands or cues at all, offer some "free treats" -- anything to make the dog feel more confident and secure.
The next dog I approach might strain to the end of its leash, wagging excitedly, then try to jump on me. This is a totally different dog! With this dog, I'm going to stand up straight and tall, and if I give any commands, it will be simple one-word ones delivered in a friendly but expectant tone. No touching or petting the dog! Even my praise will be more measured and careful. If this dog is to earn treats, I want to see him really working for them.
You can see by these two examples of how I might alter my own personal power and how the dog will see it, in order to get what I want from the dogs. For the first dog, the "straight and tall and commanding" appearance would probably make it shut down (unable to respond to any commands) or it might even be afraid of me. But for the second dog, sweet-talking and handing out cookies for no reason would likely make him respect me even less.
Because of the vast difference between dogs individual personalities, it is important that you don't use a single cookie-cutter type approach when training different dogs. And if you get the advice or read in a book to "toughen up" on your dog (or, alternately, to go slower) make sure that that's what the dog actually needs first!