I believe the key to speak English or any other foreign language fluently is to talk to natives as much as possible, practicing is the best way to achieve a good level of expertise at anything. I had English classes for many years in school but I don't think I learned much from it because they used to teach a lot of grammar and vocabulary but we didn't get to practice that much. Of course for beginners it is very important to learn a bit of every matter, but to accomplish some level of fluency one must speak a lot in that same language. I feel the "good quality" English I've learned so far first came when I moved abroad and I was forced to speak in English everyday, but still, even though I can express myself and have a conversation, I am still far away of being really fluent and that's why I keep having English lessons and writing here in Italki even some people say I don't need. We can always get better! :) Thanks for bringing up this open question and if I did any mistake, please correct me!

THANKS

Speak with people , read books , novels and stories umm these may help you improve you'r language