Not prompt engineering specific but I've done some AI workshops through tribe.ai that have gone really well.
Started with teaching an overview of the most common techniques (like Prompt Composition, RAG, Agents)
Then worked with the businesses there to identify real use cases they could apply this too.
Then workshopped which techniques make the most sense, and worked on little poc/demos.
That was 2 days and aimed at enterprise - so doesn't totally apply - but take what you like from it. (People really like tying it to their actual problems/opportunities - something they could "take home")