Yes, I did.
>If a customer stiffed you on a tip would that encourage YOU to give them better service next time they come in?
You shouldn't need any encouragement to do your job properly and professionally the first time imho.
And I wouldn't consider it being stiffed.
The couple who I poured an entire pitcher of water onto just as they sat down to dinner one night didn't tip me, and I am not confused or upset as to why.