A Bird In The Hand Is Worth Two In The Bush:
Having something that is certain is much better than taking a risk for more, because chances are you might lose everything.
Anything that is common and easy to get.
A Doubting Thomas:
A skeptic who needs physical or personal evidence in order to believe something.
A Drop in the Bucket:
A very small part of something big or whole.
A Fool And His Money Are Easily Parted:
It's easy for a foolish person to lose his/her money.
A House Divided Against Itself Cannot Stand:
Actions Speak Louder Than Words:
It's better to actually do something than just talk about it.
Add Fuel To The Fire:
Whenever something is done to make a bad situation even worse than it is.
Against The Clock:
Rushed and short on time.
All Bark And No Bite:
When someone is threatening and/or aggressive but not willing to engage in a fight.
All Greek to me:
Meaningless and incomprehensible like someone who cannot read, speak, or understand any of the Greek language would be.
Anything that is high up in the sky.
At The Drop Of A Hat:
Back Seat Driver:
People who criticize from the sidelines, much like someone giving unwanted advice from the back seat of a vehicle to the driver.
Can't Cut The Mustard.
Someone who isn't adequate enough to compete or participate.Source: www.idiomsite.com