Most restaurants will include a 10% service charge. Tipping any extra is entirely optional, although it's customary to leave a little more for good service. This will help you enjoy a similar experience if you decide to come back. Tipping taxis drivers, bartenders, baristas, and hotel staff is up to you. Tipping is not a big part of Italian or Venetian culture. So you should never feel pressured into leaving anything extra. At the same time, service employees won’t be offended if you give a large tip for exceptional service.