Teach astronomy or astrophysics.

I have the lecture slides and the midterm exam draft for Astrophysics 201. Send the files to Professor Kumar and to the curriculum office for approval, signers in that order, with the syllabus final by Monday. Before sending, check that all equations render correctly and that the exam problems reference the same notation used in lectures.

Before I hand this lecture pack to undergrads, make it easier for them to learn. Put the one concept they must master this week at the top of each slide, make worked examples findable with a visual marker, and flag any step that assumes calculus without reminding where students can review it.

After yesterday's class several students bombed the orbital mechanics problem set. I walked them through the algebra and it looks like many understand the concept but tripped on vector notation and sign conventions. I cannot tell if the failure is from my notation, the textbook, or how I presented the derivation. What is the likely cause and the best immediate fix before the next lecture?

Every semester I spend days re-editing slides and exams to fix recurring confusion: inconsistent notation, unclear problem statements, and mismatched difficulty. Which three teaching habits will reduce that churn, improve student understanding, and free up my prep time over the next terms?