She's just trying to 'earn a living'. [=to earn the money needed for food, clothing, etc.]
He will do anything to 'earn his keep'. [=to earn what is needed to support himself]
He 'earned/won his spurs' by doubling the company's profits in the past year.
(..) No, captain. Battle formations. This is where we hold them. This is where we fight! This is where they die! Earn these shields, boys! Remember this day, men... ...for it will be yours for all time. Spartans! Lay down your weapons! Persians! (..)2006 300
(..) by serving you in combat. My father trained me to feel no fear, to make spear and shield and sword... ...as much a part of me as my own beating heart. I will earn my father's armor, noble king... ...by serving you in the battle. A fine thrust. I will kill many Persians. Raise your shield. (..)2006 300