Yesterday I met a teacher with 30 years of experience of, in particular, going on tours with groups of children. (She shared some of her rules with a younger colleague.) This was a humbling experience for me - the level of control of the situation she established as acceptable for herself is impressive, and so is the level of trust her kids and their parents have in her. (Trust I measure here as the number of kids signing up for a tour with a specific teacher, relative to average.)

AFAIU, she reached this efficiency by two methods: 1) when they set off, there's nothing which is not her fault, and she doesn't have to like children or dislike them to want them stay healthy, and 2) she respects herself. Over the years, with more and more life experience behind her, this became a single 'something to protect' gut feeling.

Hope that helps:)