Finding a partner during your time away is possibly the safest ticket to fluency known to man. You'll learn more about the country, the culture, the love-bird expressions (even if you choose not to use them - 'mi querido pastelito' anyone? That's 'darling little cupcake' to anyone not studying Spanish or Soppynish), in fact, at the very least, you're going to learn a whole sub-language through text messages and emails (only ask trusted friends to translate these). You'll find yourself picking up all your partner's little vocal tics too, which will make you sound more fluent. Having someone whisper seductive things in your ear in French, Spanish or Italian is great. German, less so.