This winter I will be mostly wearing...

there are at least a bakers dozen of these kinds of hats. buy in person! Some of the flaps don't do much other than scoop the cold air directly into your ear. You need a pretty snug fit that goes well below the hear. That said, i'[m not familiar with the temps in winter london. Where I ride it's -20 after the sun sets.

Although they are a bit expensive, I wore one of the Rapha winter hats all last winter and found it really good at keeping my ears warm - it does make you look a bit of a donut though - however, its a small price to pay for warm ears

I quite fancy the red knitted one this year, when it comes out http://www.rapha.cc/knitted-hat