Ask HN: How do you teach engineers to be better writers?

We recently put in place more a formal requirement around technical specifications in my company, which has revealed a wide range of writing skills on the team. (Unsurprisingly, the engineers who were already writing extensive specs before the requirement was put in place are generally effective writers. Those who weren't doing so are less so.)

Some of the engineers are really quite poor writers. Their specs have shoddy punctuation, spelling, and grammar, but even worse are usually poorly organized, difficult to understand, and incomplete.

We are an all-remote company, so written communication is especially important. I am thinking we need to considerably elevate the importance of writing samples during the hiring process, but for engineers who are already working for us (and who in general are positive contributors), what can we do to improve their writing skills?

My experience is that writing is one of those things that some people have a knack for and others don't (kind of like coding), so I would love to hear from people who made the transition from bad to competent writing. We're not looking for Shakespeare. Just clear, grammatical, organized prose.