I didn't want to buy them candy every day (it gets expensive, especially trying to find Western candy here!), so I built an incentive system where if they raise their hand and answer a question in class, they can get up to two star-shaped post-it notes. I made it a maximum of two, so that the same students aren't encouraged to talk for the entire class! When a student gets a star, they write their name and student number on it, and then after class they turn the stars in to me. Over time, if they collect six stars, they can trade them in for candy. It's worked pretty well so far, so well that I have to figure out where I'm going to buy some more of these star post-its before today's classes

One kid actually said he'd prefer not to trade his stars in for candy, because he wanted to keep accumulating them! The rules system is kind of complicated for this, so if you do it, make sure to explain it slowly. My students are mid- to low- level, though, and got the hang of it pretty quickly. Good luck!