“Not my cup of tea”

“By the skin of your teeth”

Barely; just in time.

“Fish out of water”

Feeling uncomfortable in an unfamiliar situation.

“It’s not rocket science”

It’s not very complicated.

“The tip of the iceberg”

A small visible part of a much bigger problem or situation.

“Give someone the benefit of the doubt”

To believe someone may be telling the truth even if you are not sure.

“Take it with a grain of salt”

To not completely believe something.

“Make a mountain out of a molehill”

To make a small problem seem much bigger than it is.

“Rule of thumb”

A simple practical rule based on experience.