When I teach writing, I always have the debate in my head about whether to focus on essay or paragraph level things, or the sentence level things. For example, at the essay level you're focusing on crafting a quality hook and thesis statement, making topic sentences, ensuring that there is strong supporting evidence and actually just choosing quality main points to write about. At the sentence level, the focus is on things like word choice/vocab and grammar.
Can't you do both?....you might find yourself thinking. Yes, in an ideal world with ridiculous amounts of class time and ridiculously small class sizes, I could. But, I only have 14 weeks of teaching for 3 hours/week, with classes of 30-40 students.
So I decided to focus on the essay level. My thinking is that Korean students, especially the English majors that I teach have had an obscene amount of vocab/grammar study up until this point in their university careers and more than 2/3 of them are pretty solid with the basics and only make small mistakes that really don't affect the meaning of what they're trying to write. And for the other 1/3...well, if someone hasn't gotten a grasp of basic grammar/vocab usage by this point (like literally 1000s of hours of studying English), then there's not much that I can really do to help them in this class. And they have plenty of other general English classes and grammar classes and literature classes in which to get themselves up to speed on grammar and vocab.
Most Korean students don't really write academic essays, even in Korean, but it's actually quite a valuable skill, especially for those who are taking any sort of standardized writing test or planning to study abroad (as many of my students are). I'm hoping to give my students skills that they can use beyond just this class. Boning up on topic sentences and thesis statements and main idea selection can't be a bad thing I'm sure. I'm even learning a bit about writing through teaching these classes!
Just FYI, the book I'm using (and love) for this class is Great Essays by Keith Folse.