win (one's) spurs
To prove one's skill in a particular area and earn distinction or a good position as a result. Once you've watched the triplets for an entire day, then you'll have won your spurs as their caretaker, as far as I'm concerned. After getting my bachelor's degree, I won my spurs as a teacher by working short-term contracts in small urban schools for two years.
win one's spurs
Gain a position or attain distinction through hard work or some special accomplishment. For example, After two years of freelancing, she won her spurs as a programmer and was hired for the top job . This expression originally alluded to being knighted for some act of bravery and was being used figuratively by the mid-1500s.