GMs, how have you used ChatGPT to help run your games?

ChatGPT has been a lifeline for me as a GM with little spare time to prep and far too grand ambitions for the scale and scope of (D&D) campaign I want to run. I'm curious how other GMs have found ChatGPT and similar AI tools useful or helpful in running their own games. I'll share my own workflow below as a comment, and I hope others find it useful. I'm especially interested in any ChatGPT prompts you have found worthwhile, and you can see some of my own prompts in the examples I'll share shortly.