I remember a good lesson, learnt many years ago whilst Sail Training as a Watch Leader. If you get "stuck in" with your men and haul on the ropes as yourself, you will not notice when the sail gets caught or one of your watch gets hoisted up the mast, because he has clipped himself onto the halyard.
When you stand back from the action and observe and direct, you spot the problems more readily and are in a much better position to avert disaster.
Lesson learnt and it has served me well.