30% tips?? 18% tips?? Jeeezz... I am in the wrong business!!
10% maximum this side of the water, and only if the service is good. Some restaurants do the "a gratuity of [12-15%] is added for parties of x or more
Infact, I'm really p*ssed off with some Hilton hotels adding a £1 charity donation to my bill. That is absolutely out of order as you feel like a tight-arse telling them no. Which of course I have to as it is not my money.
And finally [rant] I hear that when you add a gratuity on your CC it almost never reaches the server! [/rant]