Where do people learn teacher handwriting? My scrawl is absolutely miserable.

This makes me think a lot about the early years of my former career (civil engineering). When I entered the profession in 1988, about 90 percent of our plans were drawn by hand, by draftsmen and women on drafting boards using ink pens, etc. When I departed the profession ten years later, more than 90 percent of our plans were drawn using CAD (only very minimal stuff was drawn by hand, and those were usually just preliminary sketches that would later be redrawn using AutoCAD).

With very similar parallels to your comments about the math notes (above), it was always quite obvious which of our technicians had worked in the “old days” by drafting by hand, and which technicians had only started their work after the CAD revolution. The old school draftsmen who made the transition to CAD were the ones whose drawings made sense, and communicated varying levels of importance via line weight, line type, and so on. Their drawings were well composed and worth saving. On the other hand, far too many folks who had only drawn using the computer drew plans where every single line had the same weight, details and callouts were squeezed into tiny places that should have never had notes squeezed into them.