I have to admit this is so brilliant and I wish I had thought of it. But I didn’t.
Here’s the idea: hand out your syllabus and have students annotate it. Let them mark up the lessons, ideas, thoughts, assignments that went well and that didn’t go well. Or, an alternate way of doing it: hand out two copies of the syllabus at the beginning of the semester. Let students know that they’ll turn in one copy at the end of the semester with their annotated comments.
I think I’m going to try this in the fall, since I have two preps that I’ve taught before (one has been about 10 years or so…) but both will represent significant revamping of the courses as we move toward a more cohesive curriculum within my department.