Don’t use a bank that charges $5 for currency conversion. If it’s anything more than an additional 1% it’s a shit bank. Always charge things in the local currency and let your bank do the conversion for +1%. Need cash? Hit a real bank ATM (not a shady kiosk one) with a debit card that refunds ATM fees and withdraw local currency for +1%. Currency conversion any other way is a complete ripoff, aside from ordering money from the bank before you leave.