To improve your English or for that matter any language, you need to focus on the following areas. One, read more and read variety. The best source for this can be a newspaper. Don't just read, write down new and difficult words in a notebook with meanings and read those words with it's meanings everyday.

Also, read some story books and that too loudly. Keep in mind the punctuations while reading loudly. It will help you understand the significance of some words and the punctuations.  

Two, speak. Speak as much as possible everyday and not just in front of a mirror but with others. It's fine to make mistakes. Mistakes are a great part of the learning process. Speak with as many individuals and different groups as possible. It will give you an opportunity to use different vocabulary, especially if the topics of discussions are different. 

Three, write. Write anything that comes in your mind. You may want to write letters to your friends, family, relatives, boss, subordinates, teachers, various government offices, celebrities or any other place or person. This variety will give you a taste of different flavours and add great value to your language skills. 

Do this everyday until you start thinking in English while speaking in English rather than thinking in your mother tongue and translating that in English before speaking. 

All the best!