Bolivia is a tough travel destination with a climate that can swing from extremely cold to extremely hot to extremely wet in just a few hours or kilometers. It's best to be practical when deciding on clothes, and wear whatever will make you most comfortable and keep you warm/cool/dry as necessary. Clothes should be hard-wearing and able to withstand getting on and off dusty vehicles and the odd rough surface. If you are going to the altiplano, wear thermals and warm clothes. You'll need a rain jacket (year-round) as well as sunglasses. Bring sturdy shoes.