In my trips, I've never had a tip refused, even in Yuan.
In general, I don't tip drivers, but I do tip bellmen. At the Shangri-La, where I stay, there is a 17% charge added to room service and restaurant charges, so I'll round the bill, but don't add anything else.
I get the feeling that, at least in major cities, and in occasions where most westerners will deal with service professionals, they would look strangely at you if you offered cigs. I don't know that for a fact, however, and I always bring Marlboros for my business contacts, where they are rapidly and gratefully accepted.
I did note, with a smile, last week that there was no tip glass at the Starbucks at the World Trade Centre.
This probably doesn't help you very much, but for what it's worth. . .
Greg
[This message has been edited by greg99 (edited 11-15-1999).]