Most writers read. The best way to improve your writing is to read, read, and read some more. Try reading the classics. They shaped the work that we see today. It will improve your vocabulary for sure, and you will see the masters utilized techniques that some of today's writers seem to have forgotten about. Try checking out some of the following:
J.R.R. Tolkien
C.S. Lewis
Alexandre Dumas
Charles Dickens (one of my favorites)
Miguel De Cervantes
Mark Twain (another favorite)
Daniel Defoe
Leo Tolstoy
Robert Louis Stevenson
Rudyard Kipling
George Eliot
Jane Austen
Fyodor Dostoevsky
Herman Melville