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).
I didn’t know it existed until I moved to Brixton. Brockwell Park has been a revelation to me, it’s beautiful with many secrets. Check out the outdoor theatre in the summer up by the old house - Midsummer Night’s Dream last year on a midsummer’s night was astoundingly good.
This is one of the only platforms on the London Underground that is not bombarded with billboard advertising. It's a reminder to myself of how an uncluttered environment can give you so much more room to think.