A great place to start the day if you are in South London is Federation Coffee in Brixton Village. The food is great and so is the coffee. This is a very chilled place where you can get both and indoor and outdoor experience (even though the whole place is under the Village roof).
My favourite restaurant as the moment which was a former boxing hall. You sit on the old spectating seats and get served butter chicken on pine cones which infuse their flavour into the food. A really different experience.
In between soho and covent garden. There ares lots of great independent shops on this street. Dover bookshop, magma, super superficial and Mint to name a few. Also if you want a cheap lunch on your work break Cafe No.1 is amazing. £2.50 jacket potatoes with cheese and beans.