Fish in troubled waters

To fist in troubled waters is to take advantage of a confused situation.  

“The young soldiers conspired to fish in troubled waters. They staged a coup d’etat at a time when the economy was in serious trouble and the people were demanding for economic reforms.”

Find one's tongue

To find one’s tongue is to be able to talk or figure out what to say.  

“I was unable to find my tongue when I saw my father for the first time in ten years.”

Fight an uphill battle

To fight an uphill battle is to struggle against very unfavorable circumstances.  

”The church fought an uphill battle when it opposed the government's population control program.”

Feeling blue

If you are feeling blue, you feel unwell, unhappy or depressed.    

”She’s feeling blue. Maybe we should invite her to see a movie or walk in the park to brighten her mood.”

Flare up

To flare up is to lose one’s temper at someone or something.  

“He flared up upon hearing that his application had been rejected.”

Fit for a king

A thing is fit for a king if it is of the very highest quality or standard.   

“The food at the wedding was fit for a king.”