There have been many gems of training wisdom that have stuck in my mind over the years
here are a few of my favourites:
Until I learned to find the fun with my dog I found training very frustrating. Our Irish Setter Kelly had a great sense of humour and an amazing ability to push people's buttons (as did Rufus) Once I started finding the amusement in their activities playing together progressed much faster - and was a lot more fun!
Self evident. With the caveat that if you rely on tiring your pooch out to find peace it may backfire badly as your dog will just get fitter and fitter and be harder to tire out!
Learned this in life. Apply it to dog play regularly. If there is a no stress way to accomplish something I'm in. Which does not mean I avoid stress at all costs - stress has a role in life but it doesn't need to be punitive, or negative.
Different dogs, and people, find value in different things. Brody taught me this in a way no other dog has. When he gets the point and wants in the game he is as driven and engaged as any dog but he needs to know the value before he decides what level of arousal to bring to the court!
This is the one I get the most pleasure from ... when the dogs show clearly show me what we need to work on, or what they want from our relationship it just makes me grin!