The best practices in teaching writing not only produce competent writers, but allow the teacher to live to tell the tale.
Here in no particular order are practices I’ve found work in teaching teens and adults to write expository nonfiction competently:
Teach one lesson multiple times in multiple ways. If the lesson’s not important enough to teach, it isn’t worth presenting in the first place.
Give explicit directions so you don’t have to keep re-explaining.
Make every writing assignment do double or triple duty. Don’t give writing prompts that do nothing other than force students to write.
Develop good writing prompts that you can reuse.
Enlist other students and outsiders to provide students with an audience.
Teach students to make checklists and use exemplars to monitor their writing behavior.
When you grade papers, focus on a strictly limited number of serious issues.
Hold students responsible for correcting their own work.