If you have never read ‘The Economist’ do yourself a favor next time you are in the bookstore and pick up a copy. Study the writing style and you’ll note that it is built around clean prose and engaging observations. Informative, but not stuffy (which is not what you’d expect, right?). Anyway, if you want to improve your writing you would do well to consult the Economist’s style manual which is available online for free.
For example, check out the discussion of ‘Americanisms.’