Some hotels automatically add a 5% to 12% service charge to your bill. Check ahead to confirm whether this charge is built into the room rate or will be tacked on at check-out. Tips are expected, and appreciated, by restaurant waitstaff (15% to 20% if a service charge isn't included), hotel porters ($1 per bag), maids ($1 to $2 a day), and taxi drivers (10% to 15%).