In preparation for our staff development I've been reviewing the notes from our staff meeting last spring to select work that both honors the wishes of staff for next steps and connects what we are to learn with our previous study on writing with Routman. Here's a good quote from Writing Essentials on the Reading-Writing connection:
Efffective teachers who have high-achieving students (including on high-stakes tests) do more writing and reading of whole texts and spend little time on "stuff" - activities about writing and reading.
So, consider your work during the school day. How much of your work with students is on whole texts as opposed to artificially created worksheets using language without context? For students to become more proficient writers they need to read lots of good pieces and not just isolated skills on worksheets.