Immersion
Anyone who has ever learned a foreign language would agree that immersion is, by far the best way to accelerate your language learning.
Multiple language exchange partners
I have language-exchange partners. They practice Chinese with me in exchange for practicing English with them. This not only helps me learn non-textbook speech, but is an easy way to make friends in a foreign country.
Flashcards and vocabulary lists
A set of small index cards with words or phrases of your new language on one side, and English on the other to drill for speed; vocabulary lists for review. Memorize sentences, not just individual words.
Learn songs and poems
This helps both with pronunciation and learning new words. It also means I can go with my Chinese friends to karaoke.
Read books
A good place to start is reading favorite English books in foreign-language translations.
Watch favorite English movies dubbed into foreign language
This way I can practice my listening comprehension without trying to understand what is going on.
Write every day
I keep a journal in my new language and write letters to my Chinese speaking friends.