I rarely tip, if anything it might just be the change, like say my bill is $19, I'll just leave a twenty dollar bill.
I really don't think a lot of people really deserve a tip for doing their jobs.
There are some people who go above and beyond their duty then yea sure they deserve a tip, but 90% of the people are doing the bare minimum of what is required of their job and they somehow feel privileged to get extra money out of you? The hell with that.
I really don't get why everyone expects tips now, waitresses, taxi drivers, sandwich makers, drink mixers, etc... (actually most venues of food). It kind of gets to a silly point where even the most menial jobs have tip cups.
Though I will say there are some rare occasions where some jobs have a significant chunk of their tips as their salary. My dad used to work as a bartender and he would maybe get like $40 for a night of work from his boss but his tips would be somewhere around $150 and this was for like 10 hours of work. Without tips he would only be getting $4 an hour. Though I don't think many places do this kind of thing anymore, I know when I tried to learn to be a bartender the boss had a set hourly wage (over the minimum wage) but he would take a significant chunk of the tips, but in the end it pretty much ended being the same thing.
I personally would prefer just a higher standard wage for previous tipping jobs and just have that somehow filtered into the cost because for those who actually depend on people tipping they can get screwed pretty badly.
And I really hate places where they put automatically force a tip on a bill and the waiter/waitress actually expects an additional tip left on the table.