I keep seeing articles about how people should be tipping more. My mom was a server for years. She also loved to go out once in a while, and couldn't always afford to leave a 20% tip, but she would always leave something. She started a very good book about being a great server. She made many "0" paychecks, but was an amazing, friendly server even when her customers weren't. She also treated every customer like they were royalty, even those who came week after week and didn't, or maybe couldn't afford to, tip well.
People loved her, remembered her, and when she had medical bills far beyond what she could pay, guess who started sending her checks... all the people she treated with so much respect and love. It goes both ways, and I really think what you put out there comes back to you in one way or another. If you dine out, please remember your server. If you're a server, give it everything you've got. I believe goodness comes back around, often when you least expect it.