earn/win (your) spurs

to do something to show that you deserve a particular position and have the skills needed for it.

He won his political spurs fighting hospital closures during his time as a local councillor in Bristol.

• a Dutch treat
• a face as long as a wet week
• a fact of life
• a factory farm
• a fag hag
• a fair shake
• a fair-weather friend
• a fairy godmother
• a fait accompli
• a fallen angel
• a fallen idol
• a fallen woman
• a fall from grace
• a fall guy
• a false alarm
• a false dawn
• a false economy
• a false start
• a family man
• a far cry from
• a far cry from something
• a fashion victim
• a fast talker
• a fast track
• a fat cat