Around Cusco by Walk, Cusco
Cusco is a fascinating city and great and easy to explore as all roads lead to (or away from ) the Plaza de Armas. Taxis are cheap - you must negotiate the price beforehand - and plentiful.
For a good day out take a taxi to a high point e.g. San Cristobal or San Blas and wander down hill visiting shops and art galleries and museums. There are also plenty of places to eat along the way or make a point of eating on Plaza de Armas. Make sure to look in door-ways in the walls - you will be surprised at what you may find!
Arm yourself with your Boleto Turistico, a camera, water, sunscreen and a hat - and comfy shoes and off you go.
Cusco is a great city to explore by foot. Most of the important sites (except Sacsayhuaman) are close to the Plaza de Armas and within easy reach. But not only is walking practical and cheap, but it also allows you to experience the entirety of the city, as you walk past old Inca walls, under Spanish colonial arcades and by the city's inhabitants enjoying their day. You get to smell the aroma of a resturant's kitchen and feel the cool mountain breeze. What a shame it must be to only see Cusco from the window of a tour bus