I prefer watching more cantonese television series, those with subtitles...cuz you can read the subtitle when you don't understand and you can learn the cantonese slangs too. When you heard a word that you don't know, you can just follow what the TV says to practice. I learned my mandarin by watching taiwanese and some chinese series. Many of my mandarin speaking friends said I speak quite well in mandarin, so I think this is a good method beside interacting with a native cantonese speaker.