I have a friend who married a Chinese girl and now lives in China. He's worked off-and-on as an English tutor. He says he found the most effective approach wasn't to stick to some curriculum - the kids get that in their English class at school - but to talk with them in English about subjects that they were motivated and enjoyed to discuss. The topics he generally chose were aspects of English culture such as music lyrics, TV shows, films, jokes, engaging stories about figures from British history. That struck me as genius - make learning the language the road you travel on to a destination that's worth going to in it's own right. It also gives them natural topics they can use when talking to native speakers.