Benjamin Franklin advocated the use of To Do lists. Peter Drucker posited that the common source of both the calvinists and the jesuits' worldwide success is that they were taught to keep a journal. Cognitive psychology's guru Daniel Kahneman advises that the best way to improve one's decisions is to start mapping them out: http://www.fastcompany.com/3013975/to-make-better-decisions-map-them-out
On the one hand, one the greatest waste is to take "gut-feel" decisions on weak hunches or prejudices - unless one is repeatedly lucky, the consequences are rarely pleasant. I've seen my share of senior managers deciding that they could send production halfway across the world because if "interface processes" were robust, production didn't need engineering to fabricate. What they missed is that engineering desperately needs production to figure out what a good design is. Or CEOs who have weird and misguided ideas about what their customers actually buy, such as thinking that styling in a car is more important than reliability and drive. In the long run such absurd decisions are often paid for by selling the ranch.
On the other hand, information has now become so overwhelming and ever present that it has become increasingly hard to keep track. I used to make a point of reading every lean book published, and I've had to let go - not mentioning, blogs, tweets and so on. Dos and Don't are everywhere, with very little evidence to back them up - or, to be precise, with very local evidence being blown out of proportion and out of context.
What to do? Buy a notebook and write your own standards. Writing it down is about the only know way to distinguish what you know from what you think. Putting it on the page, externalizing the thought, forces you to formulate and evaluate.
And, as the previous authors noted, writing things down allows us to watch how our knowledge progresses - or not - which areas change and which do not - what is predictable and what is not. Which, after all, is essential knowledge for making smarter decisions - or at least less wasteful ones.