I like to use minimum wage as a gauge to compare my tip against... Never been good at social comparisons... I figure if I see the waiter taking care of 4+ tables, I reckon this hours been good for them and I can get away with a bunch of $1s, but what if the next few hours is super slow and only one or two people show up after I'm gone? Maybe I need to lay down those ones and a five. What if today's a holiday and the 5 tables I see right now IS the breakfast/lunch/dinner rush? Gotta lay out a $10 too. If I'm the only customer when I arrive AND when I leave, definitely, it's gotta be $20 or maybe 2. If it's that confusing, just take a week off and get a job as a waiter... You'll learn real quick what YOUR preference in tips would be. You'll do the right thing. I'm sure of it.