Spoken English

Personally,
I do not prefer any English speaking classes and do not believe in their so called claims.
You can follow these points to improve your English over the period of time.
1) Read good Novels: Reading is the key here, if you want to speak good English then first learn to read. Start with some interesting novels.
2) Improve your vocabulary: Whenever you come across an unknown word, mark the same and try to understand its meaning in the context. Use a dictionary and later try to use that word in your write up.
3) Practice in front of mirror: If you want to improve your public speaking then mirror is your best friend. Try to explain your thoughts to yourself first and then once your convinced convey the same in front of a group of people.