The Zattere is a long, wide and straight walkway running the length of Dorsoduro. It is really sunny spot and has wonderful views over to the Giudecca Island. There are several reasonably priced cafes also used by locals where you can sit, relax, chat and enjoy the view and atmosphere.
At one end of Zattere is the excellent restaurant, Riviera. Also at that end is the supermarket, Conad. Halfway along Zattere, you can cut up to Schiavi for spritz and cichetti (Fondamenta Nani).