Decent book on advice for writing D&D adventures from a prolific creator. A lot of it was fairly high level and a bit on the fluffy side. I think the book would have benefited from at least one long, more fully worked example.
The target audience is very much people who want to write packaged adventures for, say, DM's Guild and less so DMs just crafting the encounters for their next D&D session. This made the book a bit less useless for me (I don't have that much interest in publishing adventures) but isn't a flaw. Although that said, Black doesn't mention game balance or play testing at all.