Try this out:
1. Get the book "Adios Strunk And White". Strunk And White is a horrible book to learn how to actually write English well. It's full of contradictions, has some bad grammar in it, doesn't follow its own advice, and tries to make English a proscriptive language rather than dynamic like it is. The Adios book basically breaks you out of the S&W mode of thinking and gets you thinking about different forms and techniques you can practice without being proscriptive.
2. Do object writing every day. There's a site http://objectwriting.com/ that has some, but you can also hit http://wordnik.com/random to get a random work. You then try to write for 10 minutes about or with that word using all your senses, including your kinetic and sense of self.
3. Blog something every day. Doesn't matter what it is but spend at least 30 minutes writing about something.
4. Learn about story structure. A good book is "The Anatomy of Story: 22 Steps to Becoming a Master Storyteller" and should fit the coder mind really well. Another book is Joseph Cambell's "The Hero with a Thousand Faces" to learn core mythical story structures.
5. Study subtext and context. If this paragraph is about what to study, the subtext is that I think most programmers can't write for shit because they're too logical, and the context is I'm telling people this on hacker news. Universally I find programmers terrible at both subtext and context of the written word.
6. Spend all the rest of your time learning to not censor yourself so that you have a voice that's yours, not the voice you think you should have.
7. Margaret Atwood had the best advice about being blocked. Paraphrased it's, "Blockage is either a problem of voice or structure. If it's voice, change who's telling the story. If it's structure, change the opening scene." She's damn right, but what do you expect from Margaret Atwood? Shitty advice?
8. Try writing in one form as if it's another. For example, write prose like it's poetry. Write poetry like its prose.
9. Get better at describing or saying the absurd. Stare at something and then describe it from unique points of view or in bizarre ways.
10. Keep a notebook and write down every idea you have, then try to make it happen. Also a great thing for songs and poems. I should actually do this more.
There ya go.