The secret of exchanging money

A small deal to some, but after all of my months of travel, I finally did find a way to exchange US money without losing half of it in the process! The not-so-secret secret: exchange at a bank.

Of course, for a scenario like my four month stint in Prague, there's no way I would have been able to bring over that much US cash, so my high-fee approach might still be unavoidable. For shorter trips though, I'd heard suggestions ranging from

• Exchange US-> foreign while in the US: lower demand means the exchange rate will be better
  Absolutely not! Or, possibly for high demand currency like euros (but then that might go against the motivation anyway), but not for currency like Czech koronas. Low demand means even lower supply, and the rates were the absolute worst.
• Exchange US->foreign at a standard currency exchange booth at your destination.
  Sometimes this is okay, but watch for unflattering exchange rates and extra fees.
  
• Exchange US->foreign by simply using foreign ATMs.
  It is possible that the rate is better than standard exchange booths, but don't forget about bank fees, especially from your US bank. Note: Bank of America loves to f*** you on all foreign transactions -- atm withdrawals, check card usage, credit card usage, etc.
• Withdraw $$ in US and exchange at destination bank. Note: probability of teller speaking English is low; bring translations.
  

Instead, I withdrew $300 in the US (ha, like that will be enough), converted $100 to euros in the Frankfurt airport to start with, and just returned from the bank to convert another $100 as I'm, yes, already running low.

$100 US at airport yesterday --> 67 euro and change
$100 US at bank today --> 75 euro and change.

Where did my first $100/67 euro go? 6 euro taxi, 15e dinner, 20e dine card deposit, 10e on university dine card (4,80 gone on first lunch), 10,5e on week-long bus pass, and just a few left (plus my new 75e :-))

Much of that is ~one-time expenses -- hopefully sailing will be smoother here on out!