Not true. Had we eaten lunch, the tip would have been roughly the same. It wasn't that I'm a "big tipper," it was the fact that I felt it was unfair to sit at a table that, had we not sat there, would most likely have been occupied by others who would have ordered / paid more, and would have resulted in a larger tip for her. Did I feel "guilt?" Yes, I did. Do I normally? No way!

I tip in proportion to the bill unless there is an overwhelming reason why I should tip more - or less. I tip a couple of dollars to store my bag, a couple of dollars when I park and a couple when I retrieve my car.

On a slight tangent, having worked as a valet parking manager at a large hotel I learned that people rarely tip when parking their cars, but usually tip when they take the car out, and it's harder to get the valets to work the evening shift because of it. Why should they run their butts off to park your car when the morning guy is gonna get the tip? Therefore, I tip in and out - try it and see how happy the valet is, and he might just park your car in a better place so it's more quickly retrieved later.