What?
Call it a day
Stop working on something
Pull someone's leg
To joke around with someone
Bite the bullet
To get something over with because it's inevitable
Cut me some slack
Don't be so critical
Get back to the drawing board
Start over
No pain, no gain
You have to work hard for what you want
Wrap your head around something
Understand something complicated
Don't count your chickens before they hatch
Don't count on something good happening until it happened
Hang in there
Don't give up
Look before you leap
Take only calculated risks
Get a taste of your own medicine
Get treated the way you have been treating others
By the skin of your teeth
Just barely
Go on a wild goose chase
To do something pointless
Don't cry over spilled milk
There's no reason to complain about something that can't be fixed
On probation...if you make another mistake, there will be consequences.
Don't put your eggs in one basket
What you are doing is too risky
Hit the nail on the head
Get something exactly right
It's a piece of cake
It's so easy
It ain't over until the fat lady sings
This isn't over yet
Don't beat a dead horse
Move on, this subject is over
He has bigger fish to fry
He has bigger things to take care of than what we are talking about now
Have your head in the clouds
Not fully concentrating in what is happening
Once in a blue moon
Rarely
Every dog has his day
Everyone gets a chance at least once
He's off his rocker