Jeans: American Apparel (alternative here).
Jumper/Sweater: Nasty Gal (get the look here).
Sandals: Saint Laurent (get the look here).
The Saint Laurent 'Jane' sandal is simple sophistication at it's very best. I had to have them- they reminded me of the first pair of proper high heels that I ever bought.... They too were a single strap sandal with a square front. I got them from Miss Selfridges in Croydon and I was 16 :)