First of all set up yourself for the ever flowing knowledge of events and happenings; also create an influential vocabulary as the more number of words you have the more impressive your writing becomes.
With Self-publishing I mean - writing novels, literature chapters, short stories and other forms of media content for newspapers, websites etc. You can also hook yourself to an advertising job in which you can write articles and short passages to attract customers, besides that give lectures about your books if you are deciding to write a novel. You can take up consultant job if you like to work as a freelancer offline or online.
There are many media companies like newspaper houses or television news channels that want expert English writers to write content for their segments, you can apply there and get entry into media jobs. There are several media careers like these waiting to get tread by fluent writers. Another good thing of developing great writing skills is that you can work as a copywriter; since the demand for business letter or content copywriter is increasing. You can invariably get a high paid part time or full time job.
Since the companies need very good brochures, newsletters and sales letters to attract customers, they will pay you big bucks if you are worthy enough, you can improve your skills to the degree where you can get an advertising marketing job, it will not only reward you with high income but also you will be able to learn business skills. You can find the jobs that you like at a listing near you or browse through various listing online.