Since style is generally seen as a peripheral quality, it's often the final one that's addressed. If students aren't adding quotes or organizing their papers, or spelling correctly, there's little sense in harping on the fact that their word choice could be a little better. Now that the seniors are finally writing functional papers, however, it's time to start addressing the style. This can be a little tricky as it doesn't involve correcting students so much as it involves convincing them that "good" probably isn't good enough. When a certain quality of writing is reached, it's not longer a matter of something being "right" or "wrong", but "better" or "best". Some students are excited to see their writing shift into something that actually sounds dynamic and professional, while others see it as just one more hoop to jump through. Teaching style is something that probably can't be done in a classroom...it really just takes practice.
So today, and on many days throughout the rest of the year, we're doing some practice work on style. It's a good problem to have, but one we'll need to address now. When students get into the "real world", they'll find no one will call them out on just being "good enough"...but the "better" or "best" writers will reap rewards they didn't even know about.