My wife has been a server in a bar for over 20 years. She is, without a doubt, the best server in existance. (No offense, 65).
Before we moved here to the Island, she worked in one of the busiest bars in the Lower Mainland. There were 4-6 girls on the floor during a day shift. She could easily sell nearly $2000 in food and drinks during a 6.5 hr shift. She'd regularly bring home about $200 a day in tips. More if she had to work night shift.
There would be girls that would beg off of certain tables, because "They don't tip". Barb wouldn't have a problem, she knows how to work people. Most of the other girls didn't like serving tables of women, not Barb, she'd have them laughing in no time. Same with old people, ya just have to have fun with them.
Even now, in the small bar that she works alone, she gets great tips. Especially in a small bar, she has your drink on the table before you're even settled in. And she knows how to upsell. Someone comes in for a coffee, "Would you like a shot of Bailey's in it?", usually they do and thank her for it. It makes for better sales, and happy customers.
And that's what it's all about. Happy customers.
So, yes, I tip well, as I've been taught to. But I do make a point of letting a server know when they are below standards.