A few days ago, someone expressed interest in finding content teaching what I think of as the "physics mindset". So not preparing for physics exams, or future classes. Nor building math skills, except incidentally. Nor of course learning about the physical world in its richness. But more, the art of... maybe call it system decomposition and approximation into, and playing with, simple models? They asked, and I didn't know of anything to suggest which has that as its focus. Any thoughts?