I give private english lessons on a one to one basis and, although I do my best to make them varied and dynamic using games (where possible), music and dialogue, I feel like I'm recycling my ideas a bit. Any activity suggestions?

In particular, I've a few teens and pre-teens who lose interest very quickly (they're getting private lessons because their parents think they need to) and I need some interesting activities that you can do with just one student (elementary level) and yourself.