I'm a Londoner.
The main difference between the US and UK is that the British are still much more reserved and social interaction is a bit more formal, especially in the south east amongst the middle classes.
We don't have such a culture of 'dating' as they do in the US, in fact before the American GIs came over during the war it was unknown in this country - until then you 'courted' women and once you started doing that you were pretty much expected to get married. That attitude is still around in the British subconscious and you still hear older people asking if you're 'courting'.
In my experience, clubs and pubs in the UK are the WORST places to meet women. British women when they go out are the most defensive of any nationality I've met - the Americans seem much more open, as do most European women. Yes we have the 'ladette' culture, but that's often a front, and anyway the most sexually forward women are usually the horrible ugly slappers.
I'd say British women respond very well to DJ approaches done well in a situation where chatting to strangers is socially acceptable - I've got loads of dates with women from my gym, at parties/balls, at art gallery private views, book launches, etc etc.