After so many years in the city, I want to appreciate the hidden gems more. Would love to hear about cool + interesting places in London that are outside the mainstream stuff.
A good place to find hidden gems is London is to look on travel blogs. They often try and find hidden gems.
I think the best option with London is to get a daily travelcard and just freestyle, Covent Garden, Soho, Notting Hill, Shoreditch, etc. Just go explore, you'll find your own hidden gems!