Following are the best ways to learn english writing and speaking quickly :-

• Read English Newspaper Daily
• Develop a habit of reading English Journals, Novels etc.
• Participate in group discussions and debate competitions.

Good Luck

Hi Ajay, You can write best English , if your English reading is more. And while we study this is automatically done, so I think your english writing should good as compare to speaking. 

So English speaking requires to listen english first. So I would advice you to watch english movies english songs and then try to speak like it. You have to make practice of using new words, you can make use of dictionary for that. Don't go for the classes. There also they tell like that only.

I hope it will help.

Thanks.