How to master English? That is a good question. Here are some obvious and not so obvious things to do.
0) Define what you want to do with English and also define what you mean by master English in your case. Being a pimp may not require complicated language skills while being a prof does require good English skills. Incidentally both professions require skills to manage people.
0.1) Know that learning a language take long time and no magic tool exists. Dictionaries are still one of most efficient way to acquire the depth of knowledge and examples.
0.2) Get a degree in English. This puts you on the cliff: do or die. Often that is the only way to learn difficult things.
0.3) Know that an ESL whose classmates are not serious is mostly useless beyond knowing that an ESL is useless. Fellow students may well decide the quality of the ESL experience. An ESL class at a high level like a part of a regular university system not as an extension program is useful, partly because the English level of classmates is high. Many of them are native speakers who are just taking an ESL as a Micky class. Many Quebecois do this and help to bring up the level of the class.
1) Read books or articles on the web.
2) Listen to radio, podcast and audio book etc. It seems audio books might be good start. I do not think most TV programs would help improve English to a really competitive level. In the end what kind of English do you like to learn? Checking podcast or free lectures on the web is the best way to do this these days.
3) Increase vocabulary.
4) Stop blaming teachers. You define your life not them. No perfect teachers nor methods will come to you.
5) Appreciate that there are many materials exist to learn English. There are tons of books for English, while there is almost none for Dutch. You can pick your favorites.
6) Do not be afraid to make mistakes at first, and then gradually and continuously perfect the skill.
7) Learn some other languages so that you become aware of comparative structural similarity among English and others.
8 ) Write blogs in English or a language you wish to polish. You become aware of the pattern of your mistakes, and realize the level of your English to depress yourself. The blog exposes clearly the idiocy of the author and will get hammered by others: most critical part is you can hammer yourself in ideas and writing etc.
9) Live in the UK. There are so many accents in the UK and people use slightly more elaborate and often twisted expressions than North Americans do. Americans may like to use a crisp short sentence with high impact. So understanding British English might give you some edge: that is, if you learn English in the UK, you will not have troubles to understand North American (NA) English. But people who learn English in NA might have difficult time to adjust to British English. Be aware that even British people have troubles to understand people who come from different regions in an extreme case. But this is irrelevant for most people…
10) Listen to high quality radio talk shows: It is valuable to listen to the discussion to acquire discussion skills: how to ask, how to interrupt a speaker, how to agree and how to go to more details.
S1) Give up. Do not waste your time if English has never been your thing and you have no clue about it. Do what you can do best. English teachers will say otherwise but English is their source of income. Being able to understand Hollywood movies prove almost nothing as far as intelligence is concerned. Is is a good hobby, if you like.
S2) Cheap advice is dead advice. A lot people giving advice have no credential. Please check the background of the author.
S3) Just using it. Even then it would take more than 4 years. If you do not have to use, then probably you spend your time in some thing more relevant.
S4) English is not enough to live comfortably in non-Anglophone countries. Learn a local language if possible. You will suffer as I do. Fluency in a local language drastically expands your horizon in Western Europe where many people harbor implicitly or explicitly healthy contempt against pan-Anglo culture. For Anglophones this is oxymoronic accusation since each Anglophone country think it is unique.
S5) Dreaming in a language does not mean you have learned the language. If I listen to podcast of a language extensively, then I can easily dream in that language. In my dream, I can freely communicate in completely incomprehensible French, Dutch or German. A Francophone Belgian told that she felt sick after she dreamed in English. “Merd!” It may mean the end of the world to some French people.