Is your primary focus Business English?

Use resources regularly – for Business English:
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Listen and speak: listen to as much English as possible – at least 4 times a week – different subjects, different accents, different methods. Start with podcasts, audio books, watch the news, follow your passions on youtube, watch films and documentaries. Speak to anyone and everyone possible in English – skype is great for this!
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♦ You can also read the news, join groups on LinkedIn.
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♦ Particularly useful is Lingq.com. I think they are excellent and their system produces excellent results. I use it myself to keep my other languages up to date.

Or your international executive career?

Use resources regularly – for international executives

♦ Make sure your English is above average: Listen to as much English as possible – at least 4 times a week – different subjects, different accents, different methods. Start with podcasts, audio books, watch the news, follow your passions on youtube, watch films and documentaries. Speak to anyone and everyone possible in English – skype is great for this! You can also read the news, join groups on LinkedIn...

Read magazines and Newspapers such as Harvard BusinessReview, The Economist, The Financial Times, or the British, American, Canadian, Australian version of your industry’s trade magazine or newspaper.  This will help you understand the mentality and culture as well as become familiar with different ways of working and learn new business skills.