My wife have recently been celebrating our (relative) independence as retirees by binge-watching recorded episodes of The Closer. We also have been fans for a long time of Blue Bloods, which we also watch regularly. As an author of medical mysteries, I'm always ready to learn something from my TV-watching (as well as my reading), and this has been no exception. Just keep an eye open for something we might use.
At somewhere around the 3/4 point of each episode of The Closer, someone says something that gives the lead character an idea of how to solve the particular mystery that is the subject for that hour. And it's made me realize that, although an author of mysteries need not hide such a clue at the first of a book, it's not a bad idea to plant a clue early in the book and then reveal the real key late in the book that solves everything.
This isn't valid in every instance, but it is helpful every once in a while. What have you discovered when watching your favorite shows that is applicable to the book you're reading or writing?