Earlier quoted context omitted.
I've gotten to a place where I start with a sketch of how I think my code ought to be used and then work backward into the implementation. So far I've gotten a lot of pushback from others on my team. And, what starts as "oh, you should just have to ____" gets really messy as the implementation takes shape.
So test-driven development (where you write the user -- the test -- first, and then the implementation)?
I think so, yes. But I start "before" the test? I write a use-case. Almost a user story, but in code. Sometimes I add comments inline with the code to try and sort out what abstractions are useful.