It is 8% Cracka.
Since the government charges them tax on 8% of the total of the bill, I make sure to tip at least that. On bills under about $10, I tip at least $2 though. Up to $100 for my family of 5, it is usually $10-$15, over $100 about $15-$20.
But other situations it depends upon whether they add a value to the service above and beyond the minimum. For example, a friend of mine tips at self-service cafeteria type places while I don't. You get your own food going down a line. You get your own silverware, drinks and refills. The only thing that someone does is come to the table and remove the plates and wipe the table. They are not waiters and don't pay taxes on the bill. They don't add any value to the service and so no tip is left. At a buffet where a watiress comes and refills your tea, takes plates away while you are eating, gets extra bread, etc, yes I leave a tip for her. Extra value was added.
Taxis, if it was a good ride, he took the best route without running up the meter, then probably I'll tip. If it is a regular cabby for me, I'll tip. But if the guy takes a longer route to run up the tab and has a shitty smelly cab, well he already got his tip.
I don't tip maids in the hotels. I don't interact with them, they get paid what they get paid and they don't get charged taxes for the cost of the stay. If perhaps they went out of their way to do something extra that they didn't need to do? Like room service? I do then. But I've stayed in places all over the states and and that has been a very rare occasion, so otherwise, no.