There are many ways to improve your English, and watching English films is one of them. You can also read English literary works like novels and poems, etc. To improve your listening ability, you can listen to English newscasts and watch movies (films). To improve your oral English skills, you can find some partners (better be native English speakers) and talk to them in English. Practice makes perfect.

Watching films is a comparatively poor way to improve foreign language ability because it is a passive activity. There are many better ways to utilize the time spent. We all enjoy watching films, but we should not kid ourselves that movies are a way to study. It's a trap.

find someone who knows good english. And then watch a lot of movies in English and read English literature.

The best technique: when you know english very well, try to always think in english, everytime you can, speak in english. You have to try to dream in english too, when you are going to sleep, think in english everytime, in that way, you are going to have a great dream in english ^^, try to put the english in your mind, never think in your language, think in english everytime, put all your websites in english : msn, facebook, youtube etc read english books and magazines, try to watch videos in english and in a few days you are going to dominate the language :)

practise and practise and practise