I am amazed at some of the design docs by my co-workers here at Google. The docs have phenomenal word economy AND read beautifully. It is literally a joy to read such docs as one sentence leads me to a question which is answered soon in the next paragraphs. The sentences use the minimum yet precise words to deliver phenomenal information density. What are ways people develop this skill?
FYI English is my second language but I did grow up learning both. I'd say my formal English is on par (if not better) than the native speakers.