Mike Shea, known as Sly Flourish in TTRPG circles, is an incredibly influential author, game designer, blogger, video creator, and much more! Mike's book, "The Lazy Dungeon Master" and "Return of the Lazy Dungeon Master" are regarded as some of the most informative and helpful books for learning to prep for your games. If you have a DM in your life who doesn't have it yet, here's your next present! (links below).
Mike and I talked a lot about his philosophies of running games, and also how he got into game design and writing!