So, with about 35 years as a gamer under my belt, I certainly don't have to read to GM tips in an RPG book before reading it? After all, what could they tell me that I don't already know?
Well, there actually is one thing or another, so I need to amend my review of Everywhen: The chapter on game mastering is awesome. It's only 10 pages, but they are packed. There's some system-specific stuff about setting difficulties first, but that already features some good general advice for most RPG genres: Look where the players have put their build points and consider that that's where they want to shine - so make sure that they get the opportunity to do so in your adventure. It also re-iterates an important idea that has been stated before in Everywhen: A failure doesn't necessarily mean that a hero has failed due to ineptitude; always err towards assuming that circumstances beyond their control thwarted them.