I used my ATM card (which also says Visa on it-- but it's a debit card). I got a few hundred euros out at a time, and paid in cash at stores, albergues, etc. There is a fee to use the ATM from both the owner of the ATM and my credit union. My credit union gave me the better exchange rate than the ATM owner, so I opted not to take the exchange rate offered by the ATM. I took an amount out that I felt comfortable carrying, but would not ruin me if I got robbed or lost my wallet somehow.
I also carried a credit card to cover emergencies-- medical or need for a hotel, rental car, etc.
I keep some money in my wallet (which is in my zipped inner vest pocket), some in my pack in a hidden pocket with a second credit card, some in a hidden pocket in the back of my vest, my son carried some of our money, and a second ATM card too. (In the past I have forgotten things when I was tired, and I've been pickpocketed.-- Oh, and I was mugged in the Barcelona subway.)