I think practice is key. Small pieces first (like, "all your toys on the floor need to be picked up by dinner time," or, "please read two chapters today") and then bigger pieces as he gets better at judging his own pace.
Great point, Erica. (You're on a roll tonight! Every time I've read one of your posts, I've wanted to write, "Yeah! What she said!"
)
In Girl Scouts, we called this "progression": start small and manageable. Take baby steps forward, but always keep asking a little bit more of the kids.
Over time, those baby steps lead to big growth. And usually you won't have big failures. Minor setbacks at worst.
