earn your spurs
earn (one's) spurs
To prove one's skill in a particular area. Once you've watched the triplets for an entire day, then you'll have earned your spurs as a caretaker, as far as I'm concerned. After getting my bachelor's degree, I earned my spurs as a teacher by working in underfunded urban schools.
earn your spursor
win your spursmainly BRITISH
COMMON If you earn your spurs or win your spurs, you show you are capable of doing something well, and can be relied on to do it well in the future. How did he earn his spurs for the toughest police job in the country? Kampelman had won his spurs as U.S. negotiator at the Madrid talks. Note: In medieval times, when a man was made a knight, he was sometimes given a pair of golden spurs.