Assuming you have a SOTA model - the thing I'd teach them is minimalism.
- Minimal tooling - Minimal system prompt - Folders + files + text
AI driven development has turned the whole development job into knowing what questions to ask + complexity reduction.
First ask the model how to do something / what options there are to do something - not just to do something. Creating moments to teach that is a challenge in itself.
After its answered go tell it to do the thing.
If they're serious though, the next step is to teach them to always ask if there is a simpler alternative with fewer dependencies.
Anything with a too magical UI is going to give them the wrong 'model' in their mind on how to think about the tool.
A bit of a hidden aspect many people seem to miss, the tone you take with the model is absolutely critical. Ask a bunch of psychology questions before having it write javascript or propose a tech stack is going to get you different results.
Finally, the semi obvious hack (and which something like claude will do automatically when in team mode) - have the model talk to another instance of itself. The model can translate your ramblings into coherent specs in the right tone and feeding that back into itself in a new session gets you the good results. Its also part of why the "first write a plan" works because it fills the context with the right tone and clear instructions.