I told my kids if there's an ounce of doubt in your mind, there's a good chance you're doing the wrong thing or you're in the wrong place.
i allowed my kids to make mistakes when they were young. It was things that wouldn't harm them. An example was I told them they got x dollars per week for the ice cream man. I suggested they buy one per day. When my son was five he bought two each of the first three days. On the 5th day he asked for more money. I refused. He learned to budget.