In most bars and restaurants tips are not expected, but 5-10 percent is optional. Apparently, if tips are given, the recipient will show extreme, and sometimes colourful, gratitude!
Again, in hotels a 5 percent tip is optional but only for great service.
Remember that taxi fares are usually increased for tourists so tipping isn’t as necessary unless you wish to reward exceptional service, when you could round up. It’s a good idea to negotiate a fare before embarking, to include the tip.