What kinds of habits should I adopt if I want to be productive and successful as a writer?
Read! Great writers are typically also great readers. And read many different genres: Newspapers, magazines, novels, non-fiction, biographies, short stories, twitter. The more you are exposed to how others write, the more you will be able to hone and refine your own voice.
And, of course, write. Try writing for your local newspaper, or a small circuation magazine. You could also write for you company or freelance for a non-profit agency or publication.
You may not be able to immediatly earn money directly from writing, but the more you write and the more feedback you get, the better you are likely to become.
And do not be afraid of rejection! This is part of the business, and take all rejection as a learning experience. Good luck!
I got a Masters of Fine Arts in creative writing (fiction), and took classes from several successful, published authors. What I learned from all of them is that they treat writing like their career (because it is). Which means they do it every single day, like any other job. Some days, it's a slog and they don't like what they write, but they do it anyway. Some days it goes better. But they believe, and I do too having seen their success, that it's important to make your body and your brain treat writing like the job you show up to do everyday. To make it part of your daily routine.
Frederick Busch, a GREAT writer who you should read, said, "I only write when the lightning strikes... I just make sure it strikes every day between 9-11am when I'm sitting at my desk." I think that sums up the industrious nature of the writers I know. I don't have a perfect record of sitting at my desk every day, but it's the goal I'm always working towards.
Stephen King's book, On Writing, details his very specific habits. He writes a certain number of words every.single.day. And Anne Lamott has my favorite book about being a writer, Bird by Bird, which I also recommend to any aspiring writer. Those could be helpful resources for you.
Best of luck!
Writing is a job. Treat it as one. Get up at a set time, and go to work. Do not go on Facebook. Do not allow yourself distractions. Turn off the phone if you have to.
If you work from home choose a room or corner and only use that space for work. Use a separate email, FB account and any other social media accounts for work related only communications. If possible get separate devices for work and personal uses.
One more thing, dress accordingly. Writing in pj's and fuzzy slippers will affect your writing.
It's important to learn how to manage your time. Some people say you should write everyday, but that isn't my style. I write when I feel compelled by an idea. It's a good idea to make space and time for writing when you are inspired to do so.
That said, it may also be helpful to set aside time for specific activities--like writing, but also other tasks and responsibilities. Being able to set a schedule for yourself can really help organize your life overall, and make it easier to give yourself the space and time to write when you are ready to do so.
Also, remember not to be too hard on yourself! Things like writing are subjective. Not everyone will love what you write, but if you do it from the heart, it will be beautiful!