[kellsbells]

Covent Garden is lovely this time of year, personally I would start there and then walk up to Regent Street and Carnaby Street.

I work just off of Oxford Street and if you don't have actual shopping to do then personally I would avoid it (maybe that's just the frustration of walking through the crowds every day talking!) although a wander around the food hall in Selfridges is lovely at Christmas time and you usually get a few free samples