Even the most seasoned travelers have to stop and consider tipping etiquette depending on the country, local custom and scenario. A general rule of thumb is that when in doubt, tip 10% in countries that have tipping practices. In countries that don’t, such as Japan, consider giving a small, thoughtful gift for service that went above and beyond.
It should be noted that even in countries without a tipping history, an increasing number of people in the service industry, especially in tourist areas, have come to expect tips from Americans, even if they don’t expect tips from locals. In those cases, tipping is discretionary.
With a few exceptions, it's always a good rule of thumb to tip housekeeping, no matter where in the world, as it's one of the most demanding service jobs for little pay.
Not least, try to tip cash or change in the local currency whenever possible. This way you can ensure staff get the money (unlike credit card tips), plus recipients don't have the hassle of exchanging currency and the associated fees. Prices throughout are in dollars, so remember to convert to local currency.
Finally, more upscale establishments and services will command larger tips, which are reflected in the price ranges.