I try not to but I also fall victim to shame often. Like some places give genuinely superb service so it feels rather rude not to tip because I have myself worked in a really fancy place once and I know both the profit margin the owners are operating on and that the staff is nonetheless treated like shit.
And in other times, it's a simple place that I plan to visit again, or have been visiting for a while. And I know how entitled and vindictive some of the people who work on those places can be.
I never pay more than 10, except 12 in a single occasion because it was a fancy place but nonetheless the prices were really good.