I found this reading especially interesting because I had never really considered my audience as a huge factor when writing. I think as a student it's easy to forget that one day your writing won't be going to the same place it always has been -- a teacher you see and talk to almost every day. Considering your audience when writing beyond just who they are, going as far as what they might be doing or where they might be, seems to be the key to writing pieces that truly speak to people.
The section on writing good introductions was also very interesting. I had known previously that a good introduction should just hook the reader in making them want to continue, but I had never considered the different ways one might do this. Using a personal story, reflecting on a current event, or pointing something out are all good strategies that do more than just talk about what the paper is going to be on.