Some US Banks (Capital One Debt Card) do not charge you for international cash withdrawals at foreign ATM’s but you will always be charged by the local bank, be sure to check what the fee is.
What will your credit cards charge you for international charges? With Chase Sapphire there is no fee.
Make sure your cards do not expire while you are on your trip, Muy importante!
My credit card gave me points when I signed up with the Chase Sapphire credit card. Signing up could pay for your flight, it paid for mine to Santiago two times over.
Let the banks know the countries you are traveling to when you go overseas.
Know the exchange rate, today October 9th 2017 the exchange rate is 1 USD = 633.381 CLP, last year it was 658.