Raining cats and dogs
Raining very hard
High as a kite
high up in the sky
Piece of cake
easy
listening
Hit the hay
Go to bed
Cry wolf
false alarm
On the fence
undecided
Baker's dozen
13
good luck
New York Minute
very fast
High on the hog
living luxuriously
Between a rock and a hard place
tough situation
Cry over spilled milk
whine/complain about something long ago
Bite your tongue
Be quiet
Dropping like flies
A leopard can't change his spots.
Dog days of summer
Hottest days in summer
Greatest thing since sliced bread
great idea
Cast iron stomach
a strong stomach; can eat/drink anything
Head over heels
excited or in love
Like a chicken with his head cut off
acting in a frenzy or acting wild
Field day
enjoyable time
Apple of my eye
someone very special
Put your foot in your mouth
say something embarrasing
Icing on the cake
When you have something good, and you get something even better