the only way is practice. no matter how much u study vocabularies or grammars, u won't be fluent unless u practice, speak as much english as u can and don't be shy or scared of making mistakes
Let me give you a express way.
Target what you wanna learn and focus on it.
e.g: you want better business english to talk with your clients
You need to listen alot, buy a business english cd,
mp3 version, put it in your mp3 and listen it all the time, when u take a bus, when u shopping, when u waiting, then u need to talk alot, talk loud and don't be shy, join some english course which have free conversation will help.
After u remember what u need to talk, then u can talk.
Do not afraid on mistake, and u may try to buy some additional cd, here is the link, it is a very nice one and they have fun topic.
One of the best ways is to get a phonics book and work on grammar and things like that. Take an ESL class if you havent. But chances are, if you can understand what i am writing, then i bet youre already fluent.