How to be excellent in English or learn English by yourself.

1. Find Good communities: That's the first thing to do. Find good communities and blogs to read every day. Put 1-2 hours / day. You won't understand the details, especially if they are written by some kind of location specific language, but you get the whole idea and the style.
2. Review grammar and syntax: Review your school courses. Tenses and forms, conditionals, passive voice... all that "crap". It's important that you have a solid mastery of the language basics to write fluently.
3. Watch and listen: My recommended channels are BBC World and Aljazeera International. Listen to podcasts and videos on the web.
4. Practice: Contribute to forums, get into the discussion and don't be afraid from being singled and turned down. Start a blog.
   
   That's it. It's not hard, it also won't happen in a day or two. Persistence is the key here. Good luck.