Get off someone’s back means to stop bothering or pestering someone.

After 10 minutes of listening to his father complain about his poor grades his son finally shouted at him “Get off my back”

Jump down someone’s throat means to get angry at someone else and shout or yell at them

Eric’s older sister jumped down his throat when he entered her bedroom without knocking first.

Lose one’s shirt means to lose money in an investment

Jason lost his shirt after the company he invested in went bankrupt.

Back to the drawing board means to have to start something for the beginning because of failure of success from previous attempts

The young inventor had to go back to the drawing board after his latest invention didn’t work as expected.

Jump the gun means to start a run (or other sporting event) before the starting signal OR to react to quickly to a situation without having all the necessary facts or information.

After his third instance of jumping the gun the runner was disqualified from the race.

The police jumped the gun when they arrested the man fro the crime; they later found out that he had a solid alibi.

Stick out one’s neck means to take a risk.

The unarmed policeman stuck out his neck when he apprehended the violent criminal.

Bend over backwards mean to try hard to please someone else.

I always bend over backward trying to please my mother-in law.

Pushing up roses means to be dead.

When asked how his father was he responded “He’s pushing up roses”.