I just set up a couple useful smart playlists in iTunes. First, I created one which matches “Date Added” “is in the last” “1″ “months” and then “limit to 25 songs selected by most recently added”

I called that “Recently added”

Then I made a similar one (with the same “limit to…” clause) but selecting on “Kind” “Starts with” “Protected”. This I called “Recently bought.”

And actually, they seem to work well…