It's more normal in fancy places, or where you genuinely want to thank a server for above and beyond service. But it's not expected, you're not rude for not doing it, and you don't do it for just any old outting.

I'll tip a bartender who mixes me a drink with 3+ ingredients that's not on their drink list, I'll tip the server who painstakingly reviews the menu with our table to make sure we don't have issues with allergies, I'll tip the barista who rushes over with a cloth to help me after I accidentally knocked over my whole coffee who tried to make me a second coffee on the house. Because that's excellent service and tipping is just an excellent way of saying thank you.

But those are exceptions to the rule.