How to write: Write, like, a lot.
Slightly less tersely:
1. Love words, love language
2. Build a good vocabulary
3. Read a lot (this helps with 2)
4. Say exactly what you mean (2 helps with this)
5. Use only as many words as are necessary to get your message across
6. The message includes the feeling or tone you want to get across (also known as the Faulkner exemption)
7. Write a lot (it takes ten thousand hours to master something, supposedly)