I think there are many ways to improve our English, but the best ones are probably three: go living in an English-speaking country for a while (2-3 months could be enough), watching movies/TV programmes in English (and in general listening to English-speaking people, also with videos on youtube), attending an English course with a mother tongue teacher. Going in an English-speaking country forces you to speak English everytime and also to listen to it during the whole day. It also helps you improving your vocabulary (also with slang terms you wouldn't ever learn or hear in Italy) and it's a way to know a different culture, which is ever good. Listening to English-speaking people "trains" your ears to the language, making it easier for you to understand, but it doesn't help you improving your speaking skills. Last but not least, attending an English course will help you improving your grammar and speaking skills and your listening ones too, but obviously isn't the same as being obliged to speak and listen to English in every moment. In conclusion, the very best way to improve our English is going in an English-speaking country for some time.