from experience
one month aboard would really help your english
anyways, till then, READ. very, very helpful. Write. practice as much as you can- work on spelling and grammer. Personally, I don't watch that much tv, but choose a program you like and watch it. you can probably find it online(sometimes they have captions in korean, so if you speak korean, don't read them
) An exercise I find useful is translating texts and stuff. not practicle when writing essays, but still. Oh, and a great way to expand your vocabulary is to translate Hebrew sings into english, making them rhyme and be as close to their original meanings as possible. good luck