Teaching writing is such a long-term endeavor! Common Core (and other) standards require that students feel comfortable writing various lengths over different spans of time, and about different subjects.
In my classroom, we engage in writing in many different ways - from "Twitter" updates, daily journaling and longer-term projects.
The following packet is an example of a slightly longer project, focused on compare and contrast writing. It has all of the objectives and materials necessary to have students brainstorm, outline, draft, revise, edit and publish their works. I would recommend adding an exemplar essay that relates to your grade level. Aside from that, it's ready to go!
It also has the 6+1 writing trait rubric attached so you can easily grade packets without any extra stapling or printing. :) It is intended for a week of focus on writing, but you could easily modify it to last longer, or to only spend part of each class period on it.
NOTE: This .zip file includes the complete PDF packet, along with customizable word documents so you can make modifications as you please!