one way ticket to london

Booked and happening! There are going to be so many things I need to do (including visa for exchange in China after this trip), but my excitement is through the roof. I've spent the past few weeks mapping and planning - the hardest part has always been finding traveling companions. This is the: I really want to go to Europe even if I have to spend a portion of it alone version. I will be staying with a friend who lives in London, but she has work so I will most likely be solo wandering with my camera. My two pals will be in Barcelona during that time, and I'm planning to meet with them afterwards in either Paris or Amsterdam. Right now it's making London plans! Any recommendations?