There is no such thing as perfect practice, because humans are imperfect. There is no such thing as perfect mindset, because humans are imperfect.
Practice does not make perfect. Practice makes permanent. Yes, we should be striving for perfection – but we should also recognize that perfection will always be beyond our reach. When we practice, we should first learn the best ways to do things. This means learning from others, not simply from our own ideas of how things "ought" to be.
I consider perfect practice/mindset/tactics to be those that I believe give me the best chance at surviving a violent encounter. Always subject to change of course which then makes them not perfect. Still at the time they are perfect. Nothing I know of that is better.