Most of us start out full of good intentions. Like lemmings in sight of Dover we head for the museums and exhibitions of the capital, intent on getting as much as we can out of our One-Day Travel Pass.
Big mistake. London has loads to offer kids, but this works strictly on the More is Less principle. Swapping notes with other irritated parents after failed days out, I've discovered that my kids aren't the only ones with the attention span of a gnat. After two hours it's time for a break. Push it any longer and the highlight of their day will have been their meal at McDonald's.
One of the best ways to feel good about trimming the time is the knowledge that you can go back again soon. We have a well-used season ticket to the Science Natural History and Victoria & Albert museums which each cost little more than a couple of visits.
Your kids may be different, but now mine are eight and 12 years old, I've found it's best to go more or less where they choose - from a selection I've made earlier. In a fit of enthusiasm I recently took them on a trip to the Tate. You can't start culture too young, I thought. You probably saw me - that irritable woman with the bored-looking kids.
I do keep the power of veto in case the kids choose some Temple of Doom, but it's never come to that - yet. And if it's me that's likely to get bored, I invite a friend with like-minded kids along to share the strain.
Our most successful trips have been when we've left the kids in charge once we've arrived. If they want a drink, give them one, and bring your own supplies. If they're tired, stop. If they decide to do something boring, remind yourself that they'll soon lose interest. With a bit of cunning they'll end up doing more or less what you'd like, but feel they've made the choice themselves.
To minimise stress, try ringing to find out when the place is likely to be quietest. And since one thwarted trip to the London Dungeon on what must have been the only day in its history that it's been closed, I always ring and check on times.
Planning the journey also pays. We've sometimes managed to make it part of the treat. The only way to visit Kew Gardens (so they loudly tell me) is by river bus; the Docklands Light Railway gives a great view of Docklands (the kids get a good laugh at the architecture) and from the end of the line you can use the foot tunnel under the Thames to Greenwich and the Cutty Sark.
Just think, in six weeks it'll all be over and we'll be wishing we could do it over again.