A hot potato

Something difficult to handle or deal with

A penny for your thoughts

A way of asking what someone is thinking

Actions speak louder than words

Peoples intentions can be judged better by what they do than what they say

Add insults to injury

To further a loss with mockery or indignity; to worsen an unfavorable situation

Speak of the Devil!

This expression is used when the person you have just been talking about arrives.

At the drop of a hat

Meaning without any hesitation; instantly

Back to the drawing board

When an attempt fails and its time to start over.

Ball is in your court

It is up to you to make the next decision or step.

Barking up the wrong tree

Looking in the wrong place or accusing the wrong person.

Be glad to see the back of

Be happy when a person leaves

Beat around the bush

Avoiding the main topic. Not speaking directly about an issue

Best of both worlds

Meaning: All the advantages

Best thing since sliced bread

A good invention or innovation. A good idea or plan.

Bite off more than you can chew

To take on a task thats far too big

Blessing in disguise

Something good that isnt recognized at first.

Burn the midnight oil

To work late into the night, alluding to the time before electric lighting

Cant judge a book by its cover

Cannot judge something based off appearance

Caught between two stools

When someone finds it difficult to choose between two alternatives

Cost an arm and a leg

This Idiom is used when something is very expensive 

Cross that bridge when you come to it

Deal with a problem if and when it becomes necessary, not before

Cry over spilt milk

When you complain about something that is not serious

Curiousity killed the cat

Being inquisitive can lead you ino an unpleasant situation

Cut corners

Cut the mustard

To succeed; to come up to expectation; adequate enough to compete or participate

Devils advocate

Being on the opposing side of an arguement

Dont count your chickens before the eggs have hatched

This Idiom is used to express "Dont make plans for something that might not happen"

Dont give up the day job

You are not very good at something. You cannot do it profesionally.

Dont put all your eggs in one basket

Dont put all your resources in one possibility

Drastic times call for drastic measures

When you are extremely desperate you need to take drastic actions.

Elvis has left the building

The show has come to an end. It's all over

Every cloud has a silver lining

Be optimistic, even difficult times will lead to better days.

Far cry from 

Very different from

Feel a bit under the weather

Feeling slightly ill

Give the benefit of the doubt

Believe someones statement, without proof

Hear it on the grapevine 

To hear rummors about something or someone

Hit the nail on the head

To do or say something exactly right 

Hit the sack/ sheets/ hay

To go to bed

In the heat of the moment

Overwhelmed by what is happening in the heat of the moment

It takes two to tango

Actions or communications need more than one person

Jump on the bandwagon

Join in on a popular trend or activity