by the seat of one’s pants—do smth. using experience and intuition rather than theory:
- I don’t follow recipes, but prefer to cook by the seat of my pants, as it were.
by the skin of one’s teeth—only just manage to get smth. accomplished:
- Making my train by the skin of my teeth, I haven’t had time to buy a paper for the journey.
Cf.: it is no skin off one’s teeth —(also: it is no skin off one’s nose)
1. it is no difficulty for a person:
- I felt it was going to benefit some people who needed it so it was really no skin off my teeth to get involved.
2. it makes no difference to a person:
- That said, I opt to wear a helmet, myself. But it’s no skin off my teeth whether other folks decide to or not.