Either cash or credit card.

According to FORBES, MY BANK TRACKER and NERD WALLET, it is recommended to buy foreign currency from your bank before you go. Generally they do not charge additional fees beyond exchange rate. Wells Fargo and Bank of America were listed as the top two banks for this type of transaction.

With a credit card, choose the local currency at point of sale to avoid currency conversion fees by the vendor. Make sure your card has no foreign transaction fees.

By and large, use your debit card to take money out of ATMs. They generally have no foreign transaction fees and reasonable conversion rates. If your bank charges ATM fees, withdraw larger amounts to avoid nickel and dime fees for smaller amounts. From experience, this is a crucial step.

Find out from your bank if they have ATM’s in the country you are traveling too that won’t charge surcharge fees. This is difficult, so best to buy before you go, or as stated, withdraw large amounts. Of course, check with your bank before you go and look for recent updates with regard to your cards and bank fees. 

Avoid using a credit card at ATMs to withdraw cash. You will pay higher fees and interest right away for cash advances. In my experience, avoid cash advances at all costs. You will pay separate interest on advances as it is considered cash and not a purchase.

Once at your destination, avoid airport Kiosks or Exchange Counters, as they generally have higher exchange rates. Use an ATM as stated above.

Everything to do with money while traveling is very fluid. Exchange rates can change over night. Always best to check with your bank and check trusted financial sources like Forbes, My Bank Tracker, and Nerd Wallet to get the latest lowdown.

Many countries will refund your VAT tax for purchases/expenses over 75 in local currency. Get a HORIZON card or whatever card is offered in the country you’re visiting, and follow the on-line registration and purchase uploads to the card. Don’t worry, most countries give you an envelop for receipts and instructions how to activate and upload the card. It is much easier to remit at the Airport when you leave. There are generally Tax remit stations located just before you leave in the Duty Free section. I’ll be honest, I have yet to receive a refund for any taxes I’ve paid and remitted for. Most likely “lost in translation.”

Download a world currency conversion app to get live exchange rates at your finger tips. There are many options on your Apple or Google store. I use World Currency Converter FOREX. It’s very user friendly.

TIP: Make sure the bank holder of cards you are using know you are traveling: WHEN, WHERE, HOW LONG. There are some that don’t require notification, but I always touch base for my own peace of mind. I didn’t once. I was in Hong Kong. I made one withdrawal for cash and the bank froze my card. It was over a weekend and holiday and live contact was impossible.