I recommend just using ATMs.

If your bank charges extra for this, maybe not, but in my 3 years in Germany I didn't visit a currency exchange once. ATMs and the occasional bank transfer did me just fine. The exchange rate at the ATM typically beats the currency exchanges too, and you don't get hit with a fee.

Make sure you're doing an ATM transaction, though, and not a cash advance: those do rack up extra fees.