- Restaurant Servers - I tip my server 20% pretty much all the time. I keep in mind that servers don't have a "wage" to back their tips up, typically. They make less an hour than they tend to pay in taxes. They work long hours, on their feet, with the sole purpose of serving me the stuff I want when I want it. If they are specifically rude, their tip drops, if they are particularly nice, their tip goes up. If they mess up some tiny thing, I don't make them suffer for it, especially if they acknowledge the issue. (another article)
- Hairdresser and Nail Salon - I tip 20% as long as I am happy with the service, and I typically don't go over that amount. This person will be in my life for a while, typically, and when I want a new appointment, I want them to want me, too! (another article)
- Car Wash guys - I give them a couple of bucks. It makes them feel appreciated (this will be mentioned later, so keep it in mind!) and makes very little difference to my life. (another article)
- Valet at a Hotel or Downtown - These guys also work pretty much off of gratuity. Also? They RUN for a living for our pleasure! I tend to tip $2 at minimum, and $5 if they're nice. I have tipped $10 and $20 before. I had a valet keep my car warm, and he had me text when I was coming down so he could turn my seat warmers on for me. He got $20 on that frigid night! (another article)
- SkyCap at the Airport - If they come get my bags from me at the curb? I'll tip them. If they do something for me that really shortens the wait, I'll tip them a little. Otherwise, I just really see them as an outside version of the check-in counter. I think they are a little bit out-dated, honestly. (another article)
- Taxi Driver - I tip my taxi Driver 10-15% of the bill, typically. They have lots of fees to pay to the taxi company, and again, their service dictates the tip. If they drive me all over the city to get where I'm going? Their tip goes down drastically. My life is in danger from the crazy driving? (another article)
- Hotel Room Cleaning Lady - This is typically $5 per day to clean up after me. They make a low wage, and do provide a service that I expect to be pretty much perfect. It's worth it when they take great care of you. (another article)
- Tour Guides, SCUBA masters, etc - These people know the area you're vacationing to, they spend LOTS of their time making sure they speak your language, are knowledgeable about all the silly, touristy questions you're about to ask, and bring you to places you couldn't find yourself. They get tipped based on how great my experience was. Typically I give some flat-rate tip... $20 a person or something like that. They are important to my vacation going well, and they'll take great care of you the next trip (say you're doing two excursions... the second will be better if you tip well the fist time!). (Another article here).
The moral of the story here? Tip the people who take care of you. They deserve it. I think we can all pretty well agree on the above standards, as they are pretty much... standard in the US.