I LOVE talking about tips. Okay, here's my rule. When I walk into that restaurant, I'm going in with a base of 15%, right? So if my waiter or waitress is absolutely average, middle-of-the-road fine, that's what they're gonna get. That's the base tip. And from there, I assess how the person waiting on me performs.
The worse they are, the lower is gets. The better, the higher. If my waiter or waitress is the absolute drizzling shits, they might get 5%. Or they might get no tip at all. Now let's say my waiter or waitress goes above and beyond, and is incredible, and everything is perfect, and they're super friendly. That tip might jump up as high as 40 or 50%.
Okay, NOW let's say the service is not amazing, right? Like my food gets there late, my cup is only refilled once or twice, that type of shit. BUT, I see my waiter or waitress working other tables, and I can tell this person is working their ass off, and they're doing their best, and they clearly just have way too much on their plate (no pun intended), that tip will not go down. In fact, if they are doing their absolute best, that tip may still go up based on my respect for them and the fact that they're putting in that work.
I've worked in food service, I know how thankless that shit is, and I respect them. So I always try to give them the benefit of the doubt.