Chill in the park with a bevvy, hire a wee boat or take a stroll round Serpentine Lake.
Cute boutiques, cafes and bakeries. Great for a stroll or some lunch.
Class options for shopping/food. Selfridges and Harrods both good options for shopping.
Slightly further afield (will require a short tube jaunt) however class food market. Will not disappoint.
Most West End theatre shows are here.