ATM transactions: Pay close attention to what the fee is for cash at bank withdrawal. For example: In Thailand you usually pay 200Baht (about 5.5 euros) per transaction as a foreigher. As a result, it is wise to debit card less often and to withdraw large amounts.
ATM transactions: Inquire well per location at which bank you receive the best exchange rate. With us it differed 25 euros for the same withdrawal between 2 banks.
Money exchange office: Find out in advance at which exchange office you will receive the best exchange rate. It is shocking how many exchange offices have a very bad exchange rate.