A tip I often give my students who are studying Spanish is to watch English-language DVDs with the Spanish subtitles on. It's probably best to start with a movie or show you have seen before and with which you are familiar with the basic plot and dialogue. As you watch the movie or show (in English), read the subtitles as you go. Stop the DVD or go back and take notes about the way the English dialogue is rendered into the language you are studying. You will find that you pick up many new idiomatic expressions this way, as well as getting to review the grammar of the language you're learning in action!
Take notes about any phrases or forms that strike you s particularly creative and also phrases or forms with which you are unfamiliar. Bring a list of new phrases to your tutor, along with the English dialogue being translated. You'll be surprised at how creative subtitle writers can be!