Are you the one like many friends of mine, who always ask for the advice on how to improve English? Strategically, as we are in a non-English speaking country, the only way to improve English is to use it. As they say, you either use it or lose it. That is why I insist that the key to improve English is just to stay motivated, keep working on it and keep practicing it. Think of it as a goal you are working towards, and just stay focus, you can do it.
But tactically, as "all roads lead to Rome", I believe there should be many ways to polish your English!
I have been quite crazy for the language. I am not sure if I set a good or bad example for you, as most people could not borrow my experience. You see, I watch English videos and listen to English audios; read English books, magazines and newspapers; surf the Internet in English; speak English and write English – all that really keep me busy every day!
Reading is your easiest way to "feel" English. It is not painful, but helps a lot. There are too many materials for you to read and you must select those you find useful, appropriate and have interest in. Besides printed materials, you can also do Web reading. To write well, one first must read well. When you read, you can highlight the words that you are not familiar with but might be useful for you. Newspapers and magazines are highly recommended for extensive reading, because the things reported are always changing, so you should never get bored of that.
You can learn English quickly by seeing English movies frequently, or watching English television and videos daily. Pick shows that interest you and try to imitate how they pronounce the words. Try to listen to some English songs and sing along with it whenever possible. If you are really poor in English, try to find English movies with subtitles. Karaoke is always fun. When you watch this kind of shows not only your verbal skill will improve but also your understanding skills. The best way, though perhaps not people's most favored, is to watch the TV news, because you can learn about how to discuss current events and talk with others in English.
Internet is a grand English world. So why not going online and "talking" to people in English? Blogging and forum discussion are pretty good ways to practice English and express yourself in a virtual world.
Also, try to find people you can practice English with in the real world. Language is for communication, which is an interactive process. Reading books, watching TV or listening to music only improve your understanding and word choice. Practice makes perfect. The best practice is conversation. You should socialize with those proficient in the language. Many English-speaking foreigners are very friendly so just make conversation wherever there is a chance. The more you speak, the more comfortable and confident you are with English. Of course, you can also take some intensive training through special tutorials, in which some of your doubts would be clarified and you are taught some more.
However, you have to be careful in finding where you "learn" your English. Someone who misleads you by giving wrong guidance would spoil your English learning. You could pick up a lot of bad habits and incorrect grammar from TV or newspapers/magazines that go rather informal sometimes. If you want to get better at English, you should fight against those persistent and chronic habits and get them fixed.