ATMs tend to spit out large bills. If the ATM gives out multiple denominations, I'll punch in an amount such that I get as many of the smaller bills as possible.

But this doesn't last long. And often my first purchases are little things, and I've run into shopkeepers that don't want to break that 50-Euro or 500HKD or 50MYR bill for a piece of fruit or trinket.

I'm assuming these are cash-only situations or I'd use a credit card.

Does anyone have tips on how or where to break big bills in various countries?