A large number of idioms are formed with the names of body parts. Here is a list of them.

First-hand

To experience something first hand is to experience it yourself

• The ideal candidate should have first-hand knowledge of accounting procedures.
• She has experienced poverty first-hand.

Best foot forward

To put your best foot forward is to do your very best

• If you put your best foot forward you’ll succeed in the interview.

Have a free hand

When you have a free hand you have the power to do what you want.

• She made it clear right from the beginning that she must have a free hand. (= She made it clear that she must have unrestricted freedom to act.)

Pull your hair out

To pull your hair out is to be very worried about something

• She has an interview tomorrow and she is pulling her hair out.

Have a hand in something

To have a hand in something is to be involved in it.

• My husband has a hand in running my business.

Have the upper hand

To have the upper hand is to have power and control over someone or a situation.

• In India upper castes still have the upper hand.

Be caught red handed

To get caught red-handed is to get caught while doing something illegal or wrong.

• He was caught red-handed while trying to cash a forged check at the bank

To be hand in glove

When two people are hand in glove, they have an extremely close relationship.

• The manager and his secretary work hand in glove.