My friend who's a lawyer has been attending training sessions at work to learn how to write shorter, more effective communication pieces. The workshop showed how a legal brief can be trimmed by half its original length when it’s well written and devoid of unnecessary wordiness.
Effective writing is effective everywhere, no matter what you want to study in college or do for a living. And one of the best ways to learn how is to read Revising Prose, which I profiled in a past post.