""2. To know how to do something.. and to watch someone doing it wrong, and to refrain from comment.
2a)Being sure they are doing it wrong, and not just differently than you.""

I found 2 and 2 a very easy to do as I got older and at tasked that I gained more experience. I learned that good lessons often results from doing something wrong, people dont normally appreciate intervention (unless they ask for it) and frequently another way of doing it is often found by greenhorns. I always saw many roads to the same result. If they screw up, no one benefits from you saying, "I did not think that would work".

When working with greenhorns, I first explain something like..."there are many routes to the same result. If I am in the lead, I probably will do if the way that fits best for me, and you can help. If you are in tge lead, you can pick whst best works for me, and I will help.