To become a better writer, you must do two things.
First, you must read good writing. That means identifying good writers and tracking down what they wrote. Thomas Sowell is an excellent writer. Choose any of these articles at random, and read it:
http://www.lewrockwell.com/sowell/sowell-arch.html
Reading good writers accomplishes two things. First, it sharpens your instinct for good writing. Knowing what good writing looks like, you are more likely to produce good written work yourself. Second, consistent exposure to good writing makes you painfully aware of bad writing, especially your own. Ask yourself, as you gaze upon a line of your own: “Would H.L. Mencken have written this drab, prolix, pedestrian sentence?” (The libertarian scholar Murray Rothbard recommended Mencken as a good example of someone an aspiring writer should read.)
If you are an absolute beginner at writing, compare your first few efforts with the works of the great writers you’ve been reading. If you don’t notice a major difference, your instincts for good writing have not been properly honed. Keep reading until — let me be blunt about this — you are embarrassed by your writing. That is the first sign that you’re on your way to becoming a good writer.
Click here to read the rest of my article (which I wrote at 1:00 in the morning when I suddenly remembered it was due today).