London is known as one of the top fashion destinations in the world, and its residents tend to echo that even in common day to day activities. Dress sharply if you don’t want to stand out as a tourist.
The average Briton’s dry sense of humor can be heavily sarcasm-based. Try not to take offense if someone starts lightly teasing you and feel free to give it back as much as they give it to you. Hey, it might even make you a life-long friend!
Restaurants and sit down cafes will usually add a 10-15% “service charge” to the bill. If this is present on your bill, additional tipping is not necessary. If your bill does not include this charge, it’s customary to tip around the same amount (10-15%).