I'll be there in late May. I booked westminster abbey and churchill war rooms because i read those need to be booked in advance. Buckingham palace only allows visits in the summer I think so can't book that. Is there anything I'm missing that needs to be booked in advance? Thanks for any suggestions and help
The only thing that really needs booking months ahead is the Warner Brothers Harry Potter Studios.
You covered the 2 major sites I tell friends to prebook, particularly Churchill's War Room, with your early bookings.
Only other one I am not sure about is the Tower of London; it has been nearly 20 years since we did, just walked up. Maybe someone can speak about that.
Relax, enjoy the trip.
Either go early and be first in line for tickets to the Tower of London or book in advance. Still go early and immediately go see the Crown Jewels. Then spend time enjoying the rest of the Tower and the ravens.
If you want to see a performance of a play at Shakespeare's Globe theater in Southwark, maybe book that in advance. In 2010, when I saw Henry IV Part 2, I felt fortunate to have gotten a ticket because the place was filled, even the Yard where we groundlings stood.
If you go, don't miss the superb museum on Shakespeare and Elizabethan drama inside the complex and the sites nearby associated with The Bard. Parts of The Rose theater have been excavated -- including the actual stage, where Shakespeare himself strode -- and can be viewed, and the site of the original Globe theater can also be seen, but it's on private property and must be viewed from a distance.
I think the advice from locals is to get to the Tower about 10 minutes after opening time. That allows the queue of nervous people who get there well before time to be served and you should be able to get your tickets in a moment. Then, as Claudia says, go straight to the Crown Jewels and then come back for the Beefeater tour.
The only other thing I can think of would be a high-demand special exhibition at one of the museums. Most are no problem at all, but they can sell out somewhat early if they're on popular topics like, say, the Royal Family, a big-name rock group, Impressionist art, etc.
Theater tickets for popular shows that are doing well enough that they won't be available via TKTS - or shows that you want really good seats for.