I came up with this reward chart for Joseph. He earns stickers for good behaviour and other things like letting me evict the colony of ear wax from his external auditory canal with a sai scooper (also known as the round end of a black hair pin). He got Dizzy (Bob the Builder's cement mixer) when he accumulated 10 stickers. His next target is the jackhammer playset for which he will need 50 stickers.
The smart kid asked me to put sticker no.11 at the 5th row. I told him, "Noooooooo...... ".
So far this form of bribery has brought good result. He greets people, behaves himself in church, keeps his toys, talks on the phone to Ah Mah and Ah Kong, feeds himself, gives his toys to his sister and makes me happy.
Maybe it'll get him to go to school next year.