TIPS - As far I know only in Japan tipping is widely considered as insult/rude.Generally there is no tipping in any situation in Taxis, Restaurants, Hotels and any other services. The services you've asked for are covered by the price given. So don't pay more. Even if you leave the cash on the table (say in restaurant), the wait staff will run after you to return it, as they will most commonly believe you forgot your change.
However a gratitude shall be shown with a gift rather than a cash tip. For whatever reason if a cash tip is to be made (to maids on an important event etc.) then there is a procedure for it. The money (not exceeding JPY10,000 shall be placed in a designated envelope.
Disclaimer: This is my personal observation in Japan for about 14 years, you may think in other countries this is observed much better than Japan. Good to know about that.
