Writing Samples
The beginning for a writer is the journal. I say this because it is the testing grounds for all your styles and ideas. If you do not keep a journal, it will be hard for you to be a good writer in almost any field.
You should write a little every day if you want to cultivate your literary skills. That's the beauty of a journal... because you don't need a revolutionary idea or original thought to write a successful entry into your journal. Other types of writing are not as forgiving; when you write poetry when you don't feel poetic or a story when you don't feel inspired, you will likely not turn out highly artistic words.