There are many ways to improve English, but it depends on what you are trying to improve.
1) If you are trying to improve listening, listen to the radio, talk to English speaking people, and watch television shows and movies.
2) If you are trying to improve speaking then speak to people in English.
3) If you are trying to improve your reading and vocabulary, then read.
4) If you are trying to improve your writing, then practice writing.
Overall, practice makes perfect.