It is recommended to leave 15-20% of the total bill, that is $15 to $20.
Tipping rates vary by the type of service provided, by the region of the country and other factors. The Emily Post Institute provides these general recommendations: 15% to 20% for sit-down restaurant service, 10% for servers at buffets (for help with drink orders and plate removal) and $1 to $2 per drink for bartenders, or 15% to 20% of the bar tab.
For valets ($2 to $5 to retrieve a vehicle), 15% to 20% for taxi drivers, hair stylists, and manicurists, and at least a couple of dollars for pizza delivery. For skycaps and hotel bellhops, figure on $2 for the first bag and $1 for each additional one. Doormen could receive a dollar or two to carry luggage or hail cabs.
For hotel staff, the institute suggests $2 to $5 per night, with money left each day (since housekeeping crews change throughout the week) and a thank-you note for the staff. Leave more if the room looks as if a hurricane went through it.
As for cash-register coin jars, there's no obligation to add money to them, although it might be worth it if you receive super service or you're a regular customer, the institute suggests.
Here are the ‘rules’ for how much to tip valet, waiters and more, shared by fox4kc.com.