Jenny Brooks
Take hand sanitizer, ziploc bags, oatmeal and ramen noodles.
Make copies of all your credit cards and IDs front and back, passport included, leave copies at home w/ parents and take copies in your suitcase.
Learn the bus system, it's significantly cheaper than taking the tube everywhere.
Eat GREAT, CHEAP sandwiches and wraps at Pret a Manger.
Don't waste a minute, wake up early, and see as much as you can!