The trick is to cycle Putney high street / Putney bridge / Fulham during rush hour. Gets your blood and piss boiling nice and evenly, no extra layers required.
I just go from Victoria into Fitzrovia. Easy peasy really.
I actually have all the layers because I'm up early walking to the train station etc. Still don't really anywhere near as much, but I is always warm.
I'm in a baselayer, polo shirt, hoody and coat, trousers and full finger gloves. My cycle is 15 minutes and I'm nice and sweaty all the way :)