COCHABAMBA - UYUNI
If you're coming to Bolivia for the first or a short time, this route is likely the best pick. Cochabamba itself is a central hub for all directions, which makes it a good starting point, but we won't cover what to do there in this route.
Mizque is worth getting off the bus at least for a lunch break. It has a beautiful pink-trimmed church and a lazy river, and will give you a good idea of typical Bolivian highland life.
Next down the road is Aiquile, which is the center of making the small guitars used for Charango, a musical style very typical in this part of the Andes.
Your first big city stop will be Sucre, the constitutional capital of the country. Outside the city to the east is Cal Orkco, a collection of dinosaur footprints impressioned on a 70 degree wall of a cement quarry, which used to be a lake floor. "Dino Trucks" go there at 9:30AM, 12:00PM (noon), and 2:30PM from the corner of Plaza 25 de Mayo in front of the cathedral if they have a quota of 4 people. The guided visit takes about 1 hour, where from a viewing platform you can use binoculars to see the display of footprints on the landscape and some models of dinosaurs to give you context.
Inside the city, make sure and visit Casa de la Libertad, Aniceto Arce (Central Plaza), important to Bolivian national history. The museum is inside a colonial-era convent, and the chapel was the meeting hall where Bolivian independence was declared in 1825.
Several other great musuems are worth your time, including the Museo de Charcas, which houses three smaller museums of colonial, ethnographic (including mummies!), and modern art. Museo de la Recoleta, a former prison now home to the works of Diego Quispe Curo and Juán Pérez Villareal. The National Archive, the Museum of Modern Art, the Museum of Ethnographic Textiles, and the Anthropological Museum, are all good ones to put on your list.
Moving on to colorful Potosi, important to the country for it's mining history and the home of the former royal mint, now the Casa Nacional de Moneda, this is a city of affluence and class. Potosi is a great place just to take photographs of its amazing and famous doorways, as well as vistas of the lights of the city at night time. Also, get out to see the Cerro Rico, where silver has been mined for over 400 years.
Now if you're headed to Uyuni, you are of course heading to the famously beautiful Uyuni salt flats, but the landscape between Potosi and Uyuni is equally haunting. However, Uyuni itself has some other treasures, namely the Train Cemetery, where relics of the rail are kept together in the desert and create a ghostly memory.