Use every opportunity when you meet a native to talk with them. This way you will be able to experience the way they talk, which constructions they use and what kind of vocabulary is most useful in everyday situations. Do not panic and do not think that you won't be able to form a fluent sentence. Even if you happen to stutter, the natives won't laugh about you. Try to be confident and see such situations as a great opportunity to improve you spoken English. After all, natives can give you some great tips about how to speak their mother tongue.