Musings on teaching writing via authentic tasks

I've learned a lot in two years of working at the Writing Center, but one of the things that is a constant presence is that writing is hard.  Even after years and years of school, writing is hard. It's supposed to be hard.  The other day, I walked in on my boss, the assistant director of the Writing Center who has a master's degree in Rhetoric and Composition, with her computer screen showing a half-finished outline, her office floor covered in annotated hard-copies of research, and her highlighter gripped like a weapon.  She saw my concerned look and said, "Dory, writing is HARD."

My point here is that writing is a continual learning process and few of us can hope to be masters at that craft.  There are a few things I can pinpoint that are essential skills, though, that might pose an especial challenge to students.

• Writing is a form of communication--a means to an end, rather than an end in itself.  A lot of students (including myself, sometimes) think of an essay as a thing they have to turn in for a grade, rather than a way of expressing and explaining their ideas to another person.  How can we help students realize the real purpose of writing, and how can we make sure we're using writing for that purpose?
• Good writing requires certain instincts: an ability to realize what the reader will be thinking while they're reading, a way with words that communicates ideas clearly, and an ability to logically lay out an argument that may or may not follow our own thought process.  How do we teach skills like this, that seem to be pretty instinctive? Can we teach them?

I'm sure there are more, but that seems to be enough to be going on with, and seems to get at the core of why it's difficult to teach writing.  Our whole system of writing a paper, turning it in to the teacher who reads it for the sole purpose of giving a grade, then getting it back, seems to go against the entire purpose of writing serving as a form of communication and a way of entering the "Great Conversation" about our topic.  I'm not entirely sure I have any ideas on how to address this issue fully, but it seems to have something to do with the  "authentic tasks" idea that gets thrown around a lot.  We should be setting up situations where students' writing is authentic, where it is being used as a genuine form of communication.