Something very easy to do.
A piece of cake
It's your decision or responsibility to take action.
The ball is in your court
To pursue a mistaken or misguided course of action.
Barking up the wrong tree
Something that seems bad or unlucky at first but results in something good.
A blessing in disguise
To initiate conversation in a social setting.
Break the ice
To take on more than you can handle.
Bite off more than you can chew
To avoid getting to the point of a conversation.
Beat around the bush
To overwork oneself by doing too many things.
Burning the candle at both ends
To study hard.
Hit the books
To work late into the night.
Burn the midnight oil
To stop working on something.
Call it a day
To be faced with two difficult choices.
Caught between a rock and a hard place
To reveal a secret.
Let the cat out of the bag
To be exactly right about something.
Hit the nail on the head
To do something in the easiest, cheapest, or fastest way.
Cut corners
To argue against something for the sake of discussion.
Devil's advocate
Feeling sick.
Under the weather
To avoid interfering in a situation that is currently causing no problems.
Let sleeping dogs lie
To join others in doing something that is currently popularor fashionable.
Jump on the bandwagon
To fail spectacularly.
Go down in flames