As the holiday season approaches and we think about expressing appreciation to all the people who do nice things for us throughout the year, it seems like a good time to review some of the rules of tipping etiquette. As is the case with all things mannerly, the rules should be based in common sense. If you’ve received especially good service, it’s nice to show your appreciation by tipping well. Conversely, if the service you’ve received is surly or unpleasant, I believe it makes sense to compensate that person commensurate with the level of service they gave.

Sometimes these things aren’t cut and dried. I have a close relative whose apartment doorman is almost constantly asleep. He misses deliveries, never brings anything up to the apartment, and does not appear to speak English as even a third language. But he also looks to be about eighty. The impulse not to tip, considering the service this person has been giving is strong, but he is there all year round (if snoozing) and he’s eighty. In that case, some tip needs to be given, but the real financial gratitude should be reserved for the other doormen who do all the work.

Doormen, parking valets, and other service people who do things all year round without being tipped deserve a cash tip at the holiday season. If you ask them, cash is by far the preferred gift. Then there’s the mailman, the paper delivery person, the trash men… I think it’s nice to do something for all of them, if you interact with them. Some people might never have seen their trash men, but I’ve always found that a little something at the holiday season makes for better service throughout the year.

Tipping rules are well known for restaurant service. A fifteen to twenty percent tip is fair for good service, and more than 20% for excellent service. When the service is poor, I leave 10%, but the waiter would have had to sneeze in my soup to elicit that kind of reaction out of me. People who work in an industry where tipping is a part of their income deserve to be compensated with respect for their work, and I think it’s important to consider a tip a mandatory thing. You should tip the maître d’ if he went above and beyond to find you a table. If you’re ordering in food, the tip should be 10% of the bill, or $5, whichever is more. It’s not fair to ask someone to deliver food, park, and wait at your door for less than five bucks. Would you do that for less than $5?

I recently received a one-percenter question about how to tip a sommelier, if you’ve purchased an expensive bottle of wine in a restaurant. The sommelier should be tipped 25% of the bottle price, or at least $25 if you’ve had a real discussion about the wine, in addition to what you’re tipping the waiter. If you choose the wine yourself, you should tip 10-20% of the cost of the bottle to the sommelier. For bartenders, the tip is usually $2 per drink. Parking valets should be tipped according to the speed of service and weather conditions. I would feel terrible about giving a valet $2 for running three blocks in the rain to get my car. It comes back to treating people with fundamental kindness and respect.