London in one day, following the river

💡Pay for the Tube with your bank card, buy nothing

You need no Oyster and no travelcard: tap your contactless card or your phone and it stops charging once you hit the daily cap. One card per person, though — sharing one across the group doesn't work.

💡London is more walking than it looks

Two Tube stops can be five minutes on foot and fifteen going down and back up stairs. Check the map before you dive in: comfortable shoes, and a rain jacket in the bag all year round.

💡The big museums are free, and the donation is voluntary

British Museum, National Gallery, Tate, Natural History, Victoria and Albert: free entry. By the door there is a donation desk that looks like a ticket office; it isn't. Temporary exhibitions do cost.

💡West End theatre can be done cheap

Day seats go on sale in the morning on each theatre's own website, and there is a discount booth in Leicester Square. Take a seat high up and to the side: you see fine and pay half.

💡In a pub you order at the bar, and the kitchen shuts early

Nobody is coming to take your order: you order and pay at the bar, giving your table number. The kitchen usually closes around nine, so dinner at ten — the way you do it at home — doesn't work here.