A gratuity is not usually added to your restaurant bill, though some may have an automatic gratuity that is charged depending on the size of your party. Waitstaff and taxi drivers receive 15-20 percent, or more if service is exceptional. Doorpersons and bellhops should receive $1 per bag, with an extra premium applied ($5-10) if there is a large amount of luggage. Valet drivers should receive a $3-5 tip.