Before your trip, make photocopies of your documents (front and back) to pack along or leave with someone at home to email to you in case of an emergency. Don't photocopy a debit or credit card — instead, keep the number in a retrievable place. It's easier to replace a lost or stolen passport if you have a photocopy.
While traveling, guard your photocopies as carefully as you would the originals. You could also store documents on a USB flash drive, or save them to a google drive or dropbox so you can access them from a computer.
It's also smart to have a backup copy of your itinerary. An itinerary-storage website (such as Tripit) is a great way to keep organized.
We pay for as much as possible with cash, using a bank that charges no or low fees for international ATM transactions.
Before you leave on your trip, inform your bank when are where you will be traveling— otherwise, they might freeze your card if they detect unusual spending patterns.
You can purchase a sim card to use in an unlocked phone for local and international calls. You can also turn off data to access wifi to use WhatsApp for free texting and calls. You can also check your cell phone carrier for international plans.