First, decide what attractions you want to see. Buckingham Palace, the Tower of London, and Westminster Abbey are all popular tourist destinations. But there are also many other interesting places to visit.
You’ll definitely want to pack lots of layers, even if you are visiting London in summer. The weather can get quite chilly and it’s nice to have a few sweaters, a jacket, and even rain gear.
With 2-3 days in London, you will be able to see several London sights and do a few activities. If this is possibly your only trip to London, you might want to plan for 5-7 days in order to check as many things off your London bucket list as possible.
If your London budget allows, try to stay as centrally located as you can. This is especially helpful with kids. There are tons of kid-friendly London hotels.
Many hotels in London have been around for a long time and are very quaint. By that I mean your room will probably be cozy and you might need to haul your luggage up a narrow flight of stairs.