Here are some easy tips to do it on your own:
1. Improve pronunciation and diction
There are a few tricks to making a vernacular accent more globally understandable.
~ Try making sure that 'air' comes out of your mouth when saying the letters, 'T, P, K' and the sound 'Ch'.
~ Focus on elongating your vowel sounds. This will also automatically slow down your rate of speech.
~ Sing English songs out loud!
~ Watch news shows on channels like CNN and BBC.
~ The web site
www.m-w.com is great for pronunciation help.
~ I would also suggest buying books on pronunciation and language.
2. Spruce up your writing skills
~ Believe it or not, you have to Read More!
~ Well-written magazines, like The Economist and India Today, are great to read not only to improve language skills but also to learn more about the world.
~ In terms of books, read what interests you. The basic goal is to read as much as you can.
People tend to forget basic grammar when writing e-mails. An e-mail is nothing more than a letter which is sent electronically.
Make sure salutations and content are professional. Use special phrases when attaching documents. For example, "Please find attached with this e-mail a report on..." This helps you sound professional.
3. Five exercises to practise every day!
i. Pretend you are a newscaster and read out the newspaper to your mirror.
ii. Do not read local newspapers. Focus on national newspapers.
iii. While reading a book, underline all the words you do not know. Look them up in the dictionary.
iv. Make a list of these words, and make sure you use at least five of them in a conversation during the day.
v. Most important, make an effort to speak in English to your friends and family.