Good topic. Growing up, I worked as a waiter/bartender/cook my whole life. It paid for school. Thus, I can comment on this.
I always tip waiter/waitresses/bartenders 20-25%. Its generally very appreciated, but then again, having been in the business, ex-restaurant folks are known as the best tippers.
I find that if you go back to a place often, and tip well, the service is so much better. At a bar, your drink order is taken with no wait, you get a few free rounds a nite and in, restaurants, the waiter will make sure your food sdoesn't sit under a heat lamp, or you get the best cuts of prime rib or steak.
As for declaring tips, its easy. Declare 10% of your total food & beverage sales for the nite. The micros machine (oor whatever system your place uses) will tell you that number at the end of the nite. For example, if you sell 700 bucks worth of food and drink, make sure your tips declared reads about 70 bucks. All credit card tips must be declared. If your credit card tips are 9-11% of total sales, you're fine, declare no cash tips. If not, make up the difference.
With respect to curbside, I've never tried that. I don't think we have that in NY. I'm sure I'd tip, however. I tip cabbies, hotel maids, the barber etc. I just find that it puts a smile on someone's face, and your much more apt to get better service.
The only tipping that annoys me, is the guy who hands out towels in the mens room of bars. Now, I'll generally tip him a buck the first couple times using the restroom if I'm in a bar for the whole nite. But after that, c'mon. Its like I'm paying to take a piss, which happens often when you are drinking Labatts all day for a Bills game at McFaddens, and I feel bad if I don't tip.