Tipping

Tipping is something that people often wonder about. In general, the standard tip is 15%. I only tip 15% if the service is OK. My go to number is 20. I return to many of the restaurants I visit. Trust me, if you are a return customer, and one that tips 20% for average service, you will get the best service possible. I tip 10% if something goes quite wrong, and only less if there is a catastrophe. 98% of my dining experience is 20% or more. There are a few additional notes on this matter. If the restaurant offers you something gratis, you figure it into the total before tipping. One example is I had a birthday meal at a great restaurant. They knew me and showered me with drinks, appetizers, and sweets. I was only charged for the meal. My tip was far more than the cost of the meal, calculated at 22% of what the entire evening would have cost me.
When it comes to tipping outside of restaurants, bellboys, concierges, valets, it is all situational. If you are at an airport Marriott, a couple of bucks for the bellboy is fine. A Ritz Carlton, however, demands at least a Lincoln. The reason being, if you can afford to stay at the Ritz, show respect to the person who was selected by the hotel as being the best candidate. Same is true with concierges.
I was once told a great story about a valet. There was a guy who had a Ferrari and was paranoid about it. He asked a valet at a very nice restaurant, "On the level, how do I get valets, to respect my car without looking like an idiot or an ass?". The valet said, "the typical tip for a car like that is $20. If you pay it up front valets know that you care about your car and, they think there might even be an extra couple of bucks if it comes back without a problem". It is a good rule and I try to follow it. Remember, just like anything else, is a sliding scale I've never owned a Ferrari, but typically I intend on tipping $7/8 for my used BMW. That means $5 up front and a couple more on return. It hasn't failed me yet, and I change my own tires, I would know if someone had been doing donuts.