When dining in a foreign country, exchange your traveler’s checks for local currency before going to a restaurant.
While traveler’s checks are pretty much accepted everywhere, don’t expect the restaurant employees to be adept at exchange rate calculation.
My best friend and I learned this the hard way dining at our first restaurant in Europe. We received far less change than we were owed and couldn’t communicate well enough to explain the problem. That, or we were taken advantage of. Either way, we didn’t make that mistake again!