You should still tip at a restaurant with bad service. Even if you received poor service, 54 percent of readers believe you should still leave something for the waiter. Only 17 percent wouldn't leave a tip, while 29 percent tip depending on the situation.
You don't need to tip your acupuncturist. Only 24 percent of people tip their acupuncturist all the time or occasionally.
You don't need to tip in countries where tipping isn't part of the culture. If you travel to countries where tipping is not practiced, you don't have to leave gratuity — 70 percent of people don't tip when the culture doesn't require it. It could be that the service charge has already been factored in.
You don't tip in self-serve restaurants. If you're serving yourself, leaving a tip for service might seem unnecessary. It seems that the majority of people agree with that sentiment: 79 percent of people polled don't tip in self-serve restaurants.