Take a walk down bokeh street
I was out with some friends around London one evening last week. I wanted lots of wet, cold, dark side-street shots, but alas we never found any (going out again on Tuesday to hunt them again).
Here's one from the footbridge over the Thames, near the London eye. Focusing very close then move up to get the blurry figures as they walk towards/away from me on the bridge.
(I'm on the train down to London atm, so no doubt this looks totally different on my laptop to what it'll be when I get to the office)