I do wonder if the 'finish on a high' comes from days when dogs were more worried than by training than they are today. If we are training positively, we should always be happy and relaxed and so should our dogs. Dogs should not be stressed if they get something 'wrong'. So, I do wonder how important this is, really. I don't shut my dogs away after training or ignore them. I say 'finished' and that means they can sniff, come for a cuddle (and probably a treat), or random interaction with me etc. just down time - nothing specific.
Again, very true. Some dogs are more affected by lack of reward than others, as well. You know, it probably all comes down to "know your dog"!
..and this is "finishing on a high". I think you're right, our dogs ARE happy and relaxed due to the way we treat them all the time.
Yes, we are training positively - but we definitely feel better when our dogs are progressing than when they are not getting it. We blame ourselves and can get frustrated with ourselves sometimes. That's why we finish on an 'easy' task. We feel better and our dogs pick up on it imo. After training we have play sessions (not dog-dog, human-dog)
I train as I walk, a bit here, a bit there, dogs doing what dogs do, sniffing, hunting, bit more training etc. I do go to a class once a week so that is more constructed, it is relaxed obedience