Buy an Oyster card, available at transit stations, to ride buses and the Tube. This card offers substantial discounts off regular fares, which run about $4 on buses and $8 on the Tube in central London. To further reduce costs, look for lodging near Tube stations and bus stops.
9. Haunt museums. London has some of the world's most fascinating museums, and many don't charge admission, except for special exhibitions. These include the British, the Victoria & Albert and the Natural History museums.
Entrance fees at other attractions can be steep; the Tower of London charges $32 per adult. Depending on how many of these sites you visit, you may save with programs such as the London Pass, www.londonpass.com.
10. Get theater discounts. The days of $10 seats in big London theaters are long gone. Tickets, although often less than on Broadway, can cost more than $100 for major shows. But you'll pay half price for many same-day performances at the TKTS booth in Leicester Square, www.tkts.co.uk.
. . . AND 5 DON'TS
And finally, for good measure, here are mistakes that could cost you a bundle in London:
1. Paying cash fares on the Tube.
2. Booking a rail ticket at the last minute. Like airfares, prices may go up as you near departure.
3. Taking a pricey city tour. Instead, check out London Walks, www.walks.com. You show up at a designated spot, pay $12 per adult and get a guided, two-hour walking tour. Dozens of themes -- pubs, ghosts, Shakespeare, the Beatles and more -- are available. Or just hop on a public bus and look around.
4. Taking lots of luggage. Excess- baggage charges on airlines can cost hundreds of dollars. Once your plane lands, you'll have to wrangle all your bags on and off the Tube (nearly impossible) or train (easier). Taxi, anyone?
5. Leaving tips for drinks at pubs and cafes. They're not expected and can really add up. You also don't have to tip if the restaurant includes a service charge, typically about 12%, in your check.