Have/with your nose in the air
Have a snobbish or disdainful attitude
- She walked past me with her nose in the air.
Keep your nose clean
Avoid trouble or situations that compromise one’s honesty
- I'd only been out of prison three months, so I was trying to keep my nose clean.
On the nose
Precisely, at an exact time
- Her description of the play was right on the nose.
Right under (one’s) nose
In an obvious location, yet overlooked
- I spent all morning looking for the book, and it was right under my nose the whole time.
It’s no skin off my (your) nose (back)
The outcome will not affect me personally
- It's no skin off my nose if you don't take my advice.
Stick your nose into something
Intrude into something that is not your affair
- You’re always sticking your nose into my business.
Powder one’s nose
To use the restroom (lavatory)
- Would you get me another drink while I go and powder my nose?
Keeping one’s nose to the grindstone
Working hard on something repetitive or tedious
- She kept her nose to the grindstone all year and got the exam results she wanted.
Have a nose for
To have natural ability at something
- As a reporter, he had a nose for a good story.