I try to learn English too, at an advanced level, to become fluent. While searching on the internet about the methods that are working, I found various tips which I would like to share with you, but in summary, with my words. So I will write here the methods which I think are the best to obtain results.
1. A great idea that I find is to approach learning a foreign language like you approached it when you learned the native language. I mean like you learned when you were a child. Not starting with reading, writing or grammar, but by listening. So it's very important to hear around you speaking a lot in English.
2. Listening English. What to listen? You can listen English Radio (on the internet, as on FM I don't know to exist), with theater programs or interviews. Watching English movies with English subtitles can also help you. You can watch on TV channels in English, but you have the disadvantage that you can not pause and return to review certain sequences (there are some TV's and TV Tuners with these features, but they may be expensive).
You can listen to BBC radio recordings (you can download from their website on podcast section). It's very good when you're on the road, you copy it on your phone, you put your headphones and listen on the go. You can write it on CD or USB memory and listen it in your car.
3. Read books in English! When you start reading these books you assume that you already understand some English. You can use also an English-Romanian dictionary, but while reading it's not OK to stop again and again for every word that you can not understand. Because in this way you'll never finish that book, or you'll loose you interest too early. Try to guess the meaning of the unknown words even if you know only 70-80 percent of the total words used. But keep in mind that you can not learn English only by reading books. You need also to speak it.
4. Connection words, basic words. These are very important and should be learned first in order to be able to maintain a basic conversation. They say there are a few hundreds of words most commonly used, which are enough to have a basic conversation in English. I would focus not on memorizing the entire English vocabulary but on these.
5. Speak English! Don't be afraid o speaking English, speak anything, without the fear of making mistakes. It's absolutely normal to make mistakes (more at the beginning, and less later), but only by speaking as much as possible you can learn. Even if at the beginning you won't like how it sounds from your mouth, think about this like a necessary step in learning this language. Everybody that speaks English fluently got through this step. If there are some natives around you don't hesitate to speak with them whenever you can.
6. Think in English!If you think first in Romanian and then translate you won't make it. Compose phrases directly in English. There are other expressions in English, other jokes, other proverbs. Use them!
7. Live in English! Set your phone and your computer language in English, read the news in English, write your shopping list in English, when you search something on the internet search it in English, etc. At home speak in English. Sometimes is difficult to convince your family to speak English with you, but it worth trying. At least you can talk and they can listen.
8. Grammar. Although there are several tenses in English, you can use only three of them: past, present and future. You can own a grammar book for possible questions, but do not rely on it. Remember when you were a kid you learned the most common verb conjugations just by listening to it, and later at school the teachers presented them to you, but you already knew most of it, because you already know to speak when you're going to school.
9. Visit the country where that language is spoken. There you can interact with natives, and your speaking abilities are improving.
10. English courses. They are useful but they are not accessible to everyone because of the high price. I would not spend my money on this until (maybe only when i would be under time pressure).
11. Make your own plan. How much you want to learn and how long. Then comply with that plan.
The plan should include both short-term and long term goals.
12. Keep in mind to pass a language test. This is to see how good you are, or how much you have to learn.
13. Think that you want to learn, not that you have to.
14. Learn English online. If you don't have the opportunity to visit that country to speak with natives, there are some websites where you can do this by writing, speaking, or even seeing. For example you search for an English person which wants to learn Romanian and you learn each other. Usually these websites gives you also the necessary tools. To find the websites search on Google for "language exchange" or "conversation exchange". Take care because some of them will ask you for money.
15. Compose texts in English. If you understand English and you speak it somewhat, you can try to write in English (I mean to compose something, like you would tell someone some stories). But remember that you must think and write directly in English.
16. Am I too old to learn English? Nobody is too old to learn something new. You know, a man learns all his life. So you can learn English even if you finished your school for several years.
17. The accent. The accent doesn't ave to be perfect. If you would listen how Chinese or Indians speaks English you would understand why. If you can have a conversation, if you can connect sentences to form longer phrases you are already good. Even if the accent is not the same as the English natives.
18. American English or British English? There are some differences between them, but I choose British English. I think that the British English has a tradition, is older, and so is more original. But this is my opinion, a lot of people thinks that the American English is easier.