The United Kingdom—American rules tend to apply, except there is no tipping in bars. Instead you can offer to buy the bartender a drink and he may take you up on it or say he’ll take the money for a drink later.
France and Italy—The tip is included in restaurants so you don’t have to put any additional money down.
Germany—Tipping is rare so in most cases you won’t need to tip.
Japan—There is no tipping and many people will be offended if you try to tip them.
China—You don’t have to tip because foreigners are already charged more for services than locals.
Egypt—You need to tip in most common situations but not taxi drivers.
Mexico—Tipping is very common and most service workers will expect a tip since they are paid very little.
Australia and New Zealand—Tipping is usually included in the price so you don’t need to add on.

More tips for tipping:
Servers in a restaurant are automatically taxed about 8% for their tips regardless of what they make, so if you don’t tip it actually costs them to serve you! So while you shouldn’t have to put up with shoddy service, think twice before you leave nothing.

That tip jar on the counter at Starbucks may make you feel obligated to contribute, but it’s actually entirely up to you whether you want to throw in a dollar or some change (although I’m sure it’s very much appreciated).

Some less frequent situations that require tipping are movers ($10 per person), a casino dealer ($1-5 per win, or you can make a side bet for them) and your wedding planner (a gift is usually more appropriate than cash).