To become fluent in English, you will have to do a number of different things. For every English learner, it could be a different combination of things but there are some common things that everyone who wants to be fluent in English needs to think about doing.
The first step to becoming fluent in English is learning how to think in English even when English is not your first language. This can be challenging to do for even the brightest and most motivated students. But rest assured that until you can think in English (and especially on a subconscious level without even trying) you will never be fluent in the language. That is to say, you must get to a point where you are not translating in your head from your language to English but you are hearing and processing and thinking in English from the first moment you hear the communication or speech.
The next question is bound to be “how do I ‘think’ in English?” That is a very good question and probably should be an independent post all to itself. But there is no question that one of the key ways to speed up that process is to immerse yourself in the language by traveling, hanging around native English speakers, consuming a huge amount of English material such books, movies, YouTube videos and magazines, and always and immediately looking up any English word you encounter that you do not know (if you have a mobile smart phone this can be a huge help because you can stop wherever you are and look up the word immediately.)
Another key thing you will have to do is learn English phrases such as phrasal verbs and idiomatic phrases. These are key to becoming fluent and speaking like a native. You have to know phrasal verbs and idioms.
Another key aspect of becoming fluent in English is verb tenses and modal verbs. Without taking the time to master these, you can kiss any pipe dream you have of becoming fluent in the language.
Finally, to become fluent in English you have to talk to yourself a lot in English. You have to role play a lot by yourself and talk to yourself in English. Also try reading English books aloud when you are alone to hear yourself speaking in English. This will build your English fluency fast!