🚅 How to get to London? ‘LeShuttle’ is definitely worth considering.

From Brussels to London is obviously easiest with the Eurostar: you arrive in the middle of the city, you don't have to drive yourself (on the left!) and you don't pay through the nose for parking.
But... The Eurostar is quite expensive, especially when you are travelling with the whole family.

That is why we have already travelled to London twice by car.
The first time, we crossed the Channel by ferry from Dunkirk. A fun experience, as you see ‘The White Cliffs of Dover’ on arrival. A lot of hassle, though. It takes quite a while before all the cars are on board, you are on the sea for about an hour and a half and then all those cars have to get off the boat again...
The second time, we took ‘Le Shuttle’ in Calais. That went very smoothly. Although it was very crowded, we were allowed to board the first train straight away. The fact that our ticket was actually meant for the train an hour later was no problem at all. After half an hour, we reached Folkestone.

We stayed twice outside the city centre. The first time in a hotel with parking. The second time we had a house swap in Lewisham: there we could park on the street for free and by train and metro we were at Big Ben in 40 minutes.

https://www.leshuttle.com/nl-nl

🚶 Stepping is often faster than driving

The London Underground is very convenient. It is a very extensive network with several lines. Just about the whole city is easily accessible that way.
With so many lines crossing each other, metro stations are often very large: long corridors, stairs up and down. You can easily spend 5-10 minutes before you get to the right platform.
A handy rule: If your destination is only 15 minutes away from your starting point, it's quicker to walk.

🖼️ Free museums

A lot of major museums in London are free: the British Museum, the National Gallery, Tate Modern, Tate Britain, etc. However, it is recommended to book your time slot in advance. That way you can be sure to get in and not have to queue for hours.
A tip: In our opinion the Churchill War Rooms are extremely interesting. Unfortunately, this is a paying activity

🎵 Musicaltickets

A ‘West End Show’ is definitely a must-see! If you want to be sure of a good spot in a particular musical, booking in advance is a good idea. However, it is also worth being flexible in your choice and simply going to the kiosk in Leicester Square on the day itself. There you can often get a good ticket at a discounted rate.
That's how we ended up with the musical ‘Matilda’, which we thought was GREAT! Our girls did not speak much English back then, but they knew Roald Dahl's book and could follow everything very well.

🎄 London at Christmas time: more people than lights

A city is often busy, that's part of it. A city at Christmas is even busier. We had also taken that into account. But the crowds in London during the holidays... We were not prepared for that. Especially in the shopping streets and in several tube stations, the crowds were unseen. We were sucked in by the mass.
Those who like things quieter are better off choosing a different period to visit London.

🔟 To avoid disappointment... You don't see Downing Street 10.

The street itself is cordoned off with bars. So you cannot get in, let alone get in front of the ‘prime minister's’ door.
If you're in the area anyway, you can definitely have a look through the closure, but we wouldn't make another detour for it.