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.

• fill out
• fill out something
• fill shoes
• fill someone in
• fill someone's shoes
• fill the void
• filthy rich
• final curtain
• final straw
• find
• Finders keepers.
• Finders keepers losers weepers.
• find feet
• find out how the land lies
• find see how the land lies
• find the time
• find the time to
• find the time to do something
• find tongue
• find your feet
• find yourself
• find your tongue
• fine by
• fine by someone
• fine kettle of fish