At restaurants a 15% tip is standard for waitstaff; as much as 20% may be expected at more expensive establishments. The same goes for taxi drivers, bartenders, and hairdressers. Coat-check operators usually expect $1-$2; bellhops and porters should get 50¢-$1 per bag; hotel maids in upscale hotels should get $4-$5 per day of your stay.
On package tours, conductors and drivers usually get $10 per day from the group as a whole; check whether this has already been figured into your cost. For local sightseeing tours, you may individually tip the driver-guide a few dollars if he or she has been helpful or informative. Ushers in theaters, museum guides, and gas station attendants do not expect tips.
A concierge typically receives a tip of $5 to $10, with an additional gratuity for special services or favors.