As someone who has lived in China for the past 6 years, in both Beijing and Shanghai, I would suggest this... Learn about the culture before you come. Tipping throughout Asia is not expected or required. Yes in some of the widely popualr tourist traps, Graet Wall, Peoples Square, Forbiden City, etc, the tour guides will ofcourse look for a tip, the westerners of course taught them that.

Regardless of the restaurant, tipping is not expected in China. Learn how to say thank you in Mandarin and I can assure you, that will be sufficient. You thowing around money as gratitude will make you look foolish. First of all, you may give it to the less senior staff member, which will make that person very uncomfortable.

Giving trinkets and gifts from your home country should be reserved for business associates, family, friends, etc, not Joe the waiter who served you Peking Duck.

This is a non tipping society, respect that and you will fit right in.