Attaining perfection in English is a gradual process that is influenced by the age and previous exposure to the language at school or in daily life. A good command in English both spoken and written definitely gives you the edge over others at national and international platforms.
Depending in the present level of English skills, the suggestions would slightly vary. To start with the simplest step forward would be to talk and have conversations in English with friends, clients and people as far as the situation permits.
Social media is a good tool to use, instead of just watching forwrds and vidoes, get into the habit of being a creative writer. Write on simple things a few lines at a time and then post it in your groups. For example, today, the PM has assured that 'our daugthers will get justice' in realtion to the shameful rape case that has rocked the country. IPL is going on, so, choose a simple fact and then start expanding on it.
With the mobile devices, you can start downloading apps, like memrise,babbel,word games. The British councel has support on the internet (https://www.britishcouncil.in/english/learn-online/learn-english-apps). They also hold courses, that you can check out.
Reading newspapers, short stories and watching English news, watching BBC news and documentaries help you to get exposure to good quality spoken English. Most people ignore the Enlgish paper supplementary, please checks these special editions or Sunday times. These 4-8 pages have good short articles on a common subject, that authors write in a professional manner. I have learn't a lot from such articles ranging from a roadtrip, classical dance, debate on law/ gender inequality etc.
Get registered in interactive sites like ISC which have excellent content in terms of professional articles and help topics. Here again, in ISC you will have a chance to interact in forum. Gradually you can pick up your skills.
If you like movies, watch English movies, courtroom dramas etc with the sub titles, this helps you get the habit of reading and hearing the words and phrases etc. Once you have done this for a month, then start learning proper grammar, explore creative writing like an essay, a summary etc.
There are free grammar software ( like grammarly etc), you can type a short article, then save it, then use the software to get the correct it, compare the mistakes, it's like self learning exercise.