The St. James' area is a must. Crockett and Jones for footwear, Geo. F Trumper for shaving accessories - don't expect to come out with much change from, well, anything. Foster and Son will make bespoke shoes for only £2850 (it's a distinct skill and not for the fainthearted), although they won't be ready for a few months - but you can give vouchers towards them for anyone who might be interested in saving up.
Check also Alfred Dunhill, which alongside the usual highly prized (and priced) ties and clothing is now starting up in gadgets - its projected keyboard is nifty, although I wouldn't want to be bashing my fingers on a table for long.
More locally we've had a branch of men's designer Simon Carter open up in Crystal Palace. Nice place, some nice ties and accessories, I'll no doubt be back shortly. Always good to see a new business opening up locally - I can only hope there will be enough interest to sustain it. I suspect my going in and not buying so much as a pair of socks this morning will have done little to help.
So, where are your favourite local shopping cubbyholes?