A bit ago I read the book Lost in the Amazon by Stephen Kirkpatrick. It's a nonfiction narrative about a fateful trip the author took to the Amazon on a photography expedition. I saw the technique in how the book opened with a tense prologue where the author was lost in the jungle--desperate, frightened, and angry at God. But then the author cut away and started Chapter one weeks before that scene actually happened, building up to the desperate moment for a good part of the book. It's a technique that could be applied to novels. I've seen Mary Higgins Clark do this, where she uses the prologue as a teaser. We know the character is going to be in that terrible position soon, and we're looking for it.
I also read biographies of people in the professions of my characters to better learn how they tick. For example, one of my characters is a cop. I'm trying to learn as much as I can about police work, so I bought the book Blue Blood by Edward Conlon, as well as several others. Biographies can give great insights into the psyche of people I might not otherwise have learned. Another example would be when I bought the book On Their Own by Martha Shirk, about kids who age out of the foster care system. One of my characters is a teenager in foster care, and I understood her better by reading that nonfiction book. I'd encourage any fiction writer to read biographies or diaries of people in similar predicaments as your characters.