Jessica Fairley: Columbia Road flower market is every Sunday morning on Columbia Road (duh) in Shoreditch. Get there early, before 8am for best deals/best photos. Also great place to check out galleries, curioso-store
Ailsa Cole: Remember it's only open on Sundays from 8am - 2pm. Go late if you want to grab a bargain! Try and see if www.sundayshoots.com is open and get your photo taken for free!