Kaifeng

• TIPS: Bills come with a mandatory 15% - yes, 15%! - service charge. This is for all party sizes. When I suggested to the waitress that this was a little high, she got her manager over, who suggested 15% was more than appropriate given the fine dining surroundings. "It's been like this for 25 years," she said, "and you're the first person to complain." Given that this is a kosher restaurant, and we Jews are, shall we say, not shy about disputing unfair charges, I found this a little rich.
  
• DO: Come here only on special occasions, as it ain't cheap, but the food, especially the shredded duck + pancakes, is undeniably yummy. I once asked them for their duck recipe: they apparently marinate it for about three days, deep fry it and then hang it to dry (or something like that) for another 24 hours. In other words, don't even think about trying this at home.
  
• DON'T Argue with the manager, as she has little time for stingy oiks who don't think their surly staff deserve the full 15% service charge (which may or may not go directly to the waitresses, but I was too intimidated by the manager to ask).
  

Atari-Ya Sushi Bar

TIPS: These are divided among waiters, waitresses, sushi chefs and management. The waitress who served me didn't seem to mind. She said it was only fair. If she's happy, then can't really argue with that.
DO: Order lots of yummy sushi. Really glad this place has opened round the corner from me. It certainly helps that this is pretty excellent value: a meal for two + beer works out at about £25.
DON'T: Forget to book ahead. The Swiss Cottage branch has only been open a couple of months, and it's already rammed every night.