Mainly through battles: a ranked win is 3 points and a ranked loss is 1. An Open War win is 1.5 and a loss is 0.5. A tournament win adds a bonus of 2 points. A draw gives 0.
The owner of a coin can also check in. A daily check-in gives 0.1 point, and every 7th day in a row adds 0.5 more. A coin must have fought at least once in the current month before check-in points land.