This is a cool book! Great advice, especially for prep-heavy RPGs like D&D. I can't say that I have personally put it to use, but that's my own inexperience as a GM.

i really like the book, especially creating the list of secrets the players might learn in the upcoming session turned out to be a great tool, so i can keep introducing new things that build upon previous discovered stuff. this way the world keeps growing as the players experience it and i don't have to know every last detail before it might even come up at the table.

Still here lurking!