In my opinion tipping is a very personal thing based on many factors. I really dislike people telling other people what they should do and judging if they have done enough or not.
I HATE the please dont forget to tip speech. When I hear that speech the tip goes down and the longer more insistent the speech is the lower the tip goes.
I also strongly dislike the "do you know what these guys end up making per hour without tips" argument. There are a LOT of jobs out there where you can punch a time clock. If one is worried about what they make per hour, perhaps they should be working one of those jobs. If I were to break down what I make coaching into per hour earnings, which I have not done and will never do as I simply don't care, it would probably be in the area of a nickel or less per hour. So what? Who cares? I love coaching and I manage to pay my bills. End of story.
If you really care how much you make per hour and/or get butt hurt when the tip jar isnt full, I hope I dont ever end up on your boat or in your shop. I believe if you do a job that you love, have fun doing it and let that show through as you give great service and provide an atmosphere that allows your customers to relax and have fun...the tips will take care of themselves.