OK, Heres the first step:
Say your bill is $20.00. Take the numbers BEFORE the decimal: 20, move the decimal once to the left: 2.0 (which would make that 2.00/two dollars) and double it. SO! Your 20% tip would be $4.00. (Leave fairly less if service wasnt good)
Say your bill is $143.98. Move the decimal once to the left: 14.3 ($14.30) and double it. Your 20% tip would be about $28.00.
Now you shouldnt have any problems being a good customer. =)

I work in a resturant, ALOT of people do not know how to act....Heres some info on how to make ure stay pleasant for US:
If you don't have a reservation, and you come in saying theres around 10 of you....PLEASE have around 10. On Sunday nights, we dread the church people because they come in, say theres only 8-10, then within the hour, theres 25 of them. COUNT CORRECTLY.
I see the worst in people...especially how messy they are. Their kids throw crackers everywhere, pizza on the floor, salad everywhere and the worst are those damn Cheerios!! I really hope you people aren't like this at home.
When you bring in your kids....keep them under control. We dont want to have to baby sit. If their screaming their head off, dont hit their hand and say shush. Because chances are, their not going to. Take them outside or in the bathroom. Other customers HATE sitting by loud children. Especially those with parents who let them run around and never sit down. UGH!!!
Don't come in and ask something stupid. I work at Buddys Pizza. Dont come in and ask if its Rio Bravo.....Dont come in and ask if we have pizza rolls. (Yes, all this has happened)
I also realize how STUPID some people are. One person will walk in, say "a table for two, non smoking"....so i seat them and they tell me, "My friend, John will join me....when he comes in, tell him where I am". Yeah, ok. I know JOHN personally.....that or he'll have his name tattooed on his forehead. LOL
I also love when people come in for take out, come up to me, look at the menu and are like "I would like......" and name off their order. I can do is look at 'em. Does it look like i have a pizza oven back there?? Go to take out dumbass.
If you have bad service, dont personally bitch to the server. Get the manager. If you have bad food, dont personally bitch to the server either. They didnt cook it. Have someone get a manager and I'm sure things will be taken care of better. --and PLEASE dont bitch to the hostesses. We only seat you. Telling us wont do any good. We'll just laugh at you after you leave.
You have NO idea how much we hate strollers. Are you THAT lazy to where u dont want to carry your kid or have them walk??? Leave those damn things home or in the car. Their a pain in the ass and they take up too much room. We get automatically annoyed when we see someone bringing them in.

Working in a resturant, I see ALOT of bad dressers. EW, we're in the new millenium for crying out loud!
Please, no more mullets. Do you HONESTLY think their cool? Especially after movies, videos, websites making fun of them??
Dont dress all in one color. Red blazer, red skirt, red panty hose and red shoes. Ummm....no.
Fannypacks are OUT. They have been for YEARS now. The worst is seeing guys wear them!!!!
Don't bring in your white trash husband into the resturant when hes wearing just a wife beater. Its fine if hes a CK model, but not when hes 60 and has the beer gut. --this happens alot when im working.
Lately, I've seen alot of teased hair. Not talking a little here and there. We're talking "Hair band groupies". Someone from back in the 80's who wore white wash jeans and one shoulder-tee shirts. Their hair was taller then their head. 80's fashions ARE coming back in, but please, not the hair.
We have some regular customers that come in with the worst hairpieces in the world. I so hope your wife thinks its hot on you....cause, we're all laughin our asses off when we see that. Do you think people think its your real hair? I sure hope not.