To help children develop good judgement, it is important to encourage them to consider the consequences of their decisions even before they made a decision. Give scenarios of possible situations they might face and talk about possible actions they could take and their consequences and not just telling them specifically what to do, which is usually much easier. For example, rather that tell a child not to run on a wet floor, you could say “the floor is wet and slippery, if you run you might slip and hurt yourself and have to go to the doctor’s or not be able to play for a while. Although, the tendency that this will restrain the child at first is unlikely. However, if the child makes a bad decision or exhibits a lack of good judgement, he will have to face whatever consequences follow and that becomes a teaching moment. Get the child to reflect on the situation and the likelihood for him to make the same choice the next time will be slim. Also, when children understand the reason why they should not make a particular choice, they are more likely to restrain themselves.
The more we are able to reflect, the better we become at making good judgements. When children cultivate the habit of reflection, they are able to think back on their actions and what they could have done differently to make a better choice the next time an opportunity shows up. Your child’s ability to think and make sound judgments will improve as he matures.