Ude o migaku is most often used in advice to the young, warning them constantly to improve their skills. In Japan discipline and training are considered essential to success in any field.
A: Wakai uchi ni isshokenmei ude o migaite okanai to shoorai komarimasu yo.
B: Isshoukenmei yatteru n desu kedo, nakanaka omou yooni dekinakute.
A: You’ll be in trouble later on if you don’t work at mastering your craft while you are young.
B: I’m doing my best, but I don’t seem to be able to achieve what I want.