Perfect your English in its homeland
Your English will improve quickly as you'll be using it 24/7 daily. Being exposed to TV, newspapers, radio and daily conversations will make you're English richer in vocabulary and more fluent. Once you dream in English for the first time, you know you reached the next level!
Good knowledge of English is one of the main requirements for most jobs, so becoming fluent will come in handy for kick-starting your career after graduation.
Learn a new language
You can also study other foreign languages at the university. They offer courses for any student for free. Besides that, you can pick up words from your colleagues in a variety of styles.