Britain's autumnal weather often brings sartorial dilemmas aplenty. What to wear to combat a frosty morning, stuffy commute, air-conditioned office and toasty pub? We're not quite in winter coat territory, nor is it warm enough to bare too many limbs. The solution? Layering. We hear this phrase thrown around in fashion every year, with little indication of exactly how or what to layer. But fear not; this season it's as easy as paint-by-numbers (thanks to the inspiration to be found both on and off the catwalk) and involves just two items: your favourite dress and some trusty trousers.