I use this writing guide for the backbone of my social studies and ELA classes. It focuses on organization of writing above the sentence level. I go over logical progression of writing, how to form a simple thesis, sources, and some simple grammar.
It also has a list of banned words and phrases that shouldn't be used in HS writing. I've used it with all ranges of students, but generally works best with students who are already at grade level when entering 9th grade. I'm happy to answer question