AIRPORT TO TOWN: I'll take a taxi if I've had a particularly bad night's sleep. It takes no more than an hour and costs around £50. Otherwise, I take the Heathrow Express to Paddington. First class costs £22. It's fast, clean and dependable. And there are always taxis at Paddington.
BEST HOTELS: The St Martins Lane Hotel 1 (45 St Martin's Lane, +44 20 7300 5500, www.stmartinslane.com) is intensely sophisticated. The service is exceptional. I like to stay at the Royal Horseguards 2 (2 Whitehall Court, 0870 333 9122, www.thistlehotels.com); it has the feel of a 19th-century London inn - smaller, elegant and hospitable. The staff are very outgoing - if you've got any problems, they'll be there in the morning apologising. New York hotels have better hairdryers, though.
BEST BUSINESS RESTAURANTS: The Asia de Cuba 3 (45 St Martin's Lane, 020 7300 5588, www.asiadecuba-restaurant.com) does such a beautiful job of presentation, you almost don't want to disturb the food. But once you dig in it's delicious - a successful blend of different cultures. The Alloro 4 (19-20 Dover St, 020 7495 4768) is very good for meetings - intimate, and not too noisy.
It offers some of the best Italian food I've ever had. There are also several excellent Asian restaurants in London, such as Nobu 5 (19 Old Park Lane, 020 7447 4747, www.noburestaurants.com), and Hakkasan 6 (8 Hanway Place, 020 7927 7000). But, generally, food isn't exactly one of the perks of London business trips - New York street vendors sell better fare than some of the eateries I've experienced. Still, I don't gain weight when I go there, so that's a good thing.
A FEW HOURS TO KILL? I recommend the hop-on, hop-off red bus tour. It's the ideal introduction to the city. When it comes to shopping, I stick mostly to Heathrow airport, as I've gotten to know where to get everything I need. Apart from that, I limit myself to trinkets, because of the high London prices. As I usually stay in the West End's theatre district, I often try to grab a play in the evenings. It's always a lot of fun. I really enjoyed seeing As You Like It and the Queen musical We Will Rock You. There is so much on offer, and it's all packed so closely together.
BUSINESS ETIQUETTE: London professionals either have a snappy, edgy style or are just downright casual - New Yorkers spend a lot trying to get that just-right business casual look. I need to upgrade my business dress to something less frumpy. New York meetings pulsate, with quick remarks and decisions; London meetings hum: you work through the agenda, people are respectful and everything gets done. The British are unfailingly polite, and American colleagues often get frustrated and end up telling them to speak their mind.
SECRETS OF THE JET SET: Walk everywhere, otherwise you'll miss the city. I always take comfortable shoes and drag whoever is with me around the streets. Don't be afraid to get lost - which you will - as people are exceptionally friendly and very patient in giving directions. I've never felt vulnerable late at night. Look both ways before crossing the street.
I get so nervous at the kerb, because you're trained from birth to look the other way. I've had a couple of close shaves, and it's very scary.
Finally, my advice to anyone is to forget the exchange rate and think only in pounds - otherwise you'd never leave your hotel.
Ann Marie Rosa is a global marketing managing director for PricewaterhouseCoopers.