Why is it that no one ever clearly articulates to young scientists that being able to write clearly and quickly is a key skill? I spend probably half of my time now writing (sometimes more!) and I have never been more grateful for a liberal arts background that included lots of writing (scientific and otherwise).
Of course, like anything else, you only get better with practice. My own first drafts tend to be full of long, difficult to parse sentences that need to be shortened and simplified in subsequent revisions. After years of experience, I know this about myself and can set up my workflow to accomodate. I am trying to get my students to write more so they can figure out their own writing habits BEFORE they have major time pressure on their writing. I am surprised by how much resistance there is to simply getting words on the page. All of them would much, much rather set up Powerpoint summaries than write things up more formally, and don't see why they should change this.