The four things every British girl (apparently) has, and other observations:
1) A Cath Kidston oilcloth purse or wallet. I was tipped off to this before I came, and lo and behold! Cath Kidston is more adorable, unique, feminine and lovely than the American Vera Bradley brand. The dots are my favorite of their prints.
2) Blazers. Men and women alike, everyone in London is wearing a blazer. Over dresses, over skirts, with flip flops or boots or loafers, with jeans and under raincoats - perhaps a remnant of the old formalities.
3) A sailor-print, lace, or animal print (by that I mean printed with actual animals, ie dogs or birds or zebras, not just the pattern of cheetah or zebra or giraffe you see most of the time) vintage-esque summer dress. Not sure how I feel about this, as they all seem to be on the awfully short side.
4) Hunter rainboots, especially in bright colors or the limited edition prints (seen above). But we knew about this already.