The teaching of writing is one of the great weaknesses of American schools. It is also the only one about which I, as a paid manufacturer of sentences, am competent to give personal advice.
I think students would benefit from one-on-one editing by their teachers. This is rare, but teachers and students who have done it tell me that it works for them as well as it did for me when I was a beginning journalist.
They like my idea of a required one-semester high school English course called Writing and Reading. Each student would produce a written piece each week and have it edited by the teacher for 10 minutes. The rest of the week, students would work in class on their next essay or read whatever they like while their classmates are edited. This spares teachers from marking up essays at home. Just 10 minutes of editing a week per student does not seem like much, but such personal contact is powerful. By the end of a semester, that would total nearly three hours of personal editing per kid, unheard of in schools today.