I run a product that generates interactive fiction (for search engine reasons I don't mention it in my comments, but there's a link to an April Fool's landing page in my post history where you can try it)

Because it's productized I need to "one-shot" the output, so I focus a lot on post-training models these days, but I've also used tricks like running wordfreq to find recently overused words and feed the list back to the model as words that cannot be used in the next generation.

Models couldn't always follow instructions like that (pink elephant problem), but recently they're getting better at it.