To keep your fingers crossed

Example

Be optimistic, and keep your fingers crossed for tomorrow exam

To have finger in every pie

Example

Doe & Smiths have a finger in every pie in the city

To have green fingers - to have a green thumb

Example

The garden is maintained so nicely, this is my aunt, she has green fingers

Crackpot brain

Example

He is used to tell weird stories, i dont know what it flows through his crackpot brain

Bird brain - pigeon brain

Example

Some tv shows gather bird brain viewers

Be the brains behind something

Example

The working plan is excellent,  I am sure the brains behind the project is Dawson

Brainchild of

Example

Popular cricket android application is brainchild of two indians

Bleeding heart

Example

Since she was a teen Helene has always  been a bleeding heart

Out on one's ears

Example

If you make such silly mistakes one more time, you should be out on your ear

Walls have ears

Example

But even in this barracks walls have ears, I had to make sure that our conversation remain confidential

To be up one's ears in debt - head over heels in debt

Example

Throughout this economic woes several families are head over heels in debt

Turn a deaf ear to - fall on deaf ears

Example

Government must stop turning a deaf ear to inmates claims

To have nothing between the ears

Example

Stating some people have nothing between ears it barely gives an idea of its meaning

To be wet behind the ears

Example

Mark's too young to work under that pressure! He's still wet behind the ears