Thanks for posting this. It was very helpful to me. I'm working on my first project in Common Lisp, and I'm still just trying to find out how to work with the system. Previously, I just loading all my files in order by hand, which isn't so bad when you keep your REPL around, but the asdf solution is really what I was looking for.
It's great to read about how an experienced developer works. Many times in a new environment, I might find out how to accomplish something, but it'll irk me because it seems tedious or inelegant. However, if one could just look over the shoulder of an experienced developer, one could see which features to use where. There is some holistic knowledge that is rarely transmitted about these complicated tools. It's as though you're given a big bag of features each of which are documented, but the task of trying to thread them together to accomplish your own goals is entirely undocumented.