How can I improve undergraduate students' writing skills? The fact: my students write badly. The source of the problem is, most likely, low quality primary and secondary education, with little emphasis on essays.
Long term solutions are beyond the scope of this question. My focus is on the short term, as a teacher of a course that asks for essays and reports. How can I help my students to improve their writing skills, even if just a little, during the course of a semester?
A potentially relevant fact: there is no awareness among students (and I would even say, among teachers) that good writing is important for their future.
Other context: I'm in a business department. My class has an average of 20 students. They come from high school. I'm new to the university so just getting to know the type of student.
This question (or its answers) seems focused on graduate students, with many examples from lab work or theses, which is not my case. This question is about us, academics. The focus here is on undergraduates who will not develop an academic career, but require such skill nonetheless, and unfortunately my university is not providing it, at least not systematically.
Several thoughts.

Give writing assignments (goes without saying). Probably more short
ones rather than fewer long ones.
Make sure students know that form matters as well as content. To
encourage students who start from a disadvantage, count improvement
as well as mastery.
Collect and critique first drafts before grading the final work.
Allow students to resubmit essays.
More problematical: have students critique each others' work before
submission. Those critiques could even be private, so that students
wouldn't be calling each other out before the teacher, only noting
when some argument was unclear to them.

Of course this will be time consuming for you and for them. To do it properly you may have to revise the course objectives to include work done to improve writing - at the expense of &quot;more content&quot;.