How did you go about teaching your toddler how to use a spoon and/or a fork?

My 14 month old son is excellent at self-feeding. I was thinking about teaching him how to use a spoon. What is the best way to go about it? What foods is best for him to practice with? I have some left over baby food and cereal from when he first started on solids that are still good, would that be a god thing to use? It will just go to waste otherwise.