I love the Ask 3 rule! Although, I think they naturally started to do this when we did this during math centers.
When they get stuck, I will sit down and walk them through problem solving why their code didn’t work. Often, before I even have a chance to get through it all, they will catch their error.
I take time for them to share their successes. I can’t tell you how much art I have printed for them! I even had a couple use this for their Science fair project.