Good luck with your helper work. One thing I will add to what has been said; it is all about attitude, confidence and being able to read dogs. Part of being a good helper is being a good actor. There are times to act impressed by the dog, times to act like the dog is scaring you to build the dog's confidence or reward a behavior. There are also times to act like you are not impressed and portray yourself as a viable adversary and serious threat. The key is to know when and how to do each to get the desired result.
I work Police K-9's and SchH dogs regularly. I decoy much harder and much more seriously for the Police dogs and they quickly learn that I am a serious threat. This can be accomplished by simply changing your state of mind. Dogs are excellent at reading body language and that is a skill you will need to learn. How to portray yourself as a very intimidating threat simply by a look or change in breathing or posture. You can convery a lot to a person or a dog by a look. However, you must have the ability to follow through with these subtle threats. I was teaching a new handler how to decoy recently and wanted him to pressure one of the dogs. This guy is a very good cop, in excellent shape but was smiling the whole time. He loves his job and really enjoys working dogs. But, the dog just wasn't getting the serious message I wanted from him. After a brief chat they both got the message.
It is very similar to what was posted earlier with the bar fight analogy. With the correct attitude and mind set you can easily convince a dog that you mean business and are a person the dog should be concerned about. Think of the vibe that Mike Tyson in his prime gave off to his opponents when he simply entered the ring. His look and demeanor told it all. There was absolutely no doubt he had very bad intentions for his opponent and conveyed it very well.
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